Using a powerful technology called single-cell proteomics, these detectives track molecules called proteins, cell by cell, to shed new light on how the human body works and how diseases develop. Their tenacity has helped make Cedars-Sinai one of the world’s leading institutions in this rapidly evolving frontier of medical science.

Proteomics, the study of the complete set of proteins expressed by an organism, provides a powerful window on what is happening in the human body. That’s because these hard-working molecules carry out nearly every bodily activity.

The challenge is that a typical laboratory sample of human tissue contains thousands of cells, and each cell is packed with multiple copies of thousands of different proteins.

To connect each protein to the correct cell, single-cell proteomics investigators rely on equipment called mass spectrometers. These machines, which are like highly sophisticated scales, use magnetic forces to separate proteins by their molecular weight or mass. With the proteins sorted, investigators can identify them and match them to the cells that contained them.

Using mass spectrometry, Cedars-Sinai investigators have uncovered new types of heart cells. They are unlocking secrets of how our arteries work. And they are developing proteomics technology that can analyze thousands of cells in minutes instead of hours or days.

More discoveries are on the way. At the Cedars-Sinai Board of Governors Innovation Center, mass spectrometers operate around the clock, seeking, sorting and scrutinizing proteins. The machines are part of the center’s Alfred E. Mann Single Cell Precision Medicine Center.

But it’s really the people, not the machines, who are most responsible for Cedars-Sinai’s leading role in this nascent discipline. Below are profiles of three investigators who rank among the top international experts in single-cell proteomics.

The Visionary

It is impossible to conduct a serious discussion of proteomics without mentioning Jennifer Van Eyk, PhD, who helped pioneer this discipline and recently served as president of the international Human Proteome Organization, the field’s premier scientific association. In 2024 she was listed by The Analytical Scientist as one of the world’s 20 most impactful analytical scientists in human health.

“I started working in proteomics before the word ‘proteome’ was coined in the 1990s,” Van Eyk said in a recent interview. “At that time, I was among just a few scientists around the world who were trying to accurately measure proteins on a large scale.”

Van Eyk’s passion is clinical proteomics, which applies scientific discoveries to patient care. At Cedars-Sinai, she directs the Smidt Heart Institute’s Advanced Clinical Biosystems Research Institute, which she founded in 2014 to foster collaboration among scientists, physicians and biotechnology companies.

One of Van Eyk’s most recent achievements was to co-lead a study revealing that cardiomyocytes, the muscle cells of the heart, are not all identical. Using single-cell proteomics, she and her colleagues discovered two new hybrids of cardiomyocytes that produce both heart- and neuron-related proteins. The team is now exploring whether gender differences in cardiomyocytes could affect how a person responds to medications.

Given that drugs generally target proteins, Van Eyk sees single-cell proteomics as a critical new tool for troubleshooting disease treatments and testing new ones.

“Suppose you have a drug that works 50% of the time,” she said. “Does that mean it's working 50% in every cell, or is it working 100% in 50% of the cells? The answer is important because it allows you to fix the problem. Single-cell proteomics can provide that information.”

As director of Basic Science Research in the Barbra Streisand Women’s Heart Center and the Erika J. Glazer Chair in Women’s Heart Health, Van Eyk has a special focus on cardiology. But she also collaborates on studies of conditions as diverse as pulmonary hypertension, breast cancer and amyotrophic lateral sclerosis, also known as ALS.

Van Eyk envisions a bright future for single-cell proteomics.

“We're finding such unexpected things that you couldn't even have thought about before using these methodologies,” she said. “And the discoveries will continue until we've done enough, and then we'll do the next breakthrough in the technology.”

The Racer

Before she was a scientist, Sarah Parker, PhD, was an aspiring Olympic speed skater. Having narrowly missed that goal in 2002, she now applies the Olympic motto of “Faster, Higher, Stronger – Together” to proteomics.

The together aspect is important. Parker, an associate professor of Cardiology and Biomedical Sciences, co-directs the Proteomics and Metabolomics Core at Cedars-Sinai with Van Eyk. During her decade-long career at Cedars-Sinai, she has been a versatile team player while heading her own laboratory that has produced breakthrough studies in atherosclerosis, cancer and proteomics applications.

Parker is also striving to make single-cell technology faster and stronger through higher volume. With colleagues, she is perfecting so-called “high throughput” techniques that enable a mass spectrometer to analyze proteins in tissues from multiple people. The bigger the sample, the better the chance of finding rare cells and discovering something new about the body.

“The challenge is that to perform this analysis, you need to quickly turn and burn through a lot of cells in a reasonable amount of time,” Parker said.

In 2023, she co-led an influential Cedars-Sinai study that devised a novel solution: Get rid of the dead time between loading one sample and acquiring the data from a subsequent sample by toggling back and forth between the two processes. Using this system, a mass spectrometer can identify more than 1,000 proteins in individual cells in 15 minutes, allowing nearly 100 cells to be measured each day. This rate was double the industry standard at the time.

In current research funded by the National Institutes of Health, Parker is using single-cell proteomics to investigate how hormones influence aortic aneurysms, the bulges in the wall of the main artery from the heart that can rupture, with life-threatening results. The potential clinical application is to design better drug treatments for both males and females with this serious condition.

Parker’s longtime interest in the cardiovascular system grew from courses she took as a college student and athlete preparing for a career in sports psychology.

After retiring from professional sports, Parker learned about proteomics while earning a PhD in physiology at the Medical College of Wisconsin in Milwaukee. As a postdoctoral fellow at Johns Hopkins University in Baltimore, she was mentored by Van Eyk, who later moved her laboratory to Cedars-Sinai and encouraged Parker to join her there.

“I really liked everything about Cedars-Sinai,” Parker said, including the collaborative ethos. “On the proteomics team, we’re on most of each other’s papers—not all of them, but most of them.”

The Data Scientist

To Jesse Meyer, PhD, an assistant professor in the Department of Computational Biomedicine at Cedars-Sinai, health comes down to one number: age.

“Aging is the biggest predictor of most diseases,” he said. “If we can deeply understand aging, then we can potentially delay the onset of many diseases at once instead of spending so much energy targeting each disease separately.”

The quest for that knowledge led Meyer to proteomics and data science, an interdisciplinary field that uses statistics, computer science and mathematics to uncover meaningful patterns in large sets of data.

“What is so cool about proteomics is that proteins are tiny machines in your cells, that we have so many of them and that they are so diverse,” he said.

For data scientists like Meyer, quantifying these tiny machines is a labor of love.

Meyer first encountered protein biochemistry and mass spectrometry as an undergraduate studying plants at the University of Minnesota in Minneapolis. After completing his PhD in chemistry and biochemistry at the University of California, San Diego, he decided to use his skills to help people. That led him to take a postdoctoral research fellowship at the Buck Institute for Research on Aging in Novato, California, where he learned to apply proteomics, and the study of small molecules called metabolites in cells and tissues, to problems related to aging.

Meyer established his laboratory in 2020 and relocated to Cedars-Sinai in 2022, where his research includes developing informatics tools for proteomics, optimizing single-cell workflows, and applying these approaches to single-cell and single muscle fiber proteomics studies of muscle aging.

Based on his achievements in proteomics at such an early career stage, the US Human Proteome Organization presented Meyer with the 2025 Robert J. Cotter New Investigator Award. That year’s advances by Meyer included co-leading the creation of a user-friendly web platform for analyzing mass-spectrometry data that facilitates sharing among multiple collaborators.

In a recent publication, in the peer-reviewed journal Cell Genomics, Meyer and his colleague, project scientist Amanda Momenzadeh, PharmD, offer an overview of the current state of single-cell proteomics. Despite the field’s many challenges, they conclude that single-cell proteomics is poised to transform our understanding of biological complexity.

At this critical moment, you would need a crystal ball to foretell the future of this dynamic science. But judging from their track records, Cedars-Sinai investigators are likely to be at the forefront of the next big innovation.

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So brings more than 15 years of leadership experience in research and clinical care to her new role. She will spearhead Cedars-Sinai’s growing genomics initiatives and serve as a strategic leader for the integration of genomics into clinical practice while overseeing genetics and genomics services across the Cedars-Sinai Health System.

“We are excited to welcome Dr. So to Cedars-Sinai, knowing her exceptional expertise and leadership in clinical genetics will be a significant asset to the burgeoning prenatal, pediatric and adult genetics programs,” said Shlomo Melmed, MB, ChB, executive vice president of Medicine and Health Sciences and dean of the Medical Faculty at Cedars-Sinai. “Her appointment will ensure Cedars-Sinai remains at the forefront of genomic endeavors, benefiting and transforming the lives of our patients.”

So has joined Cedars-Sinai from the University of California, San Francisco (UCSF), where she was chief of the Division of Medical Genetics and medical director of Adult Genetics. She was also director of the institution’s designation as a National Organization for Rare Disorders Rare Disease Center of Excellence. During her tenure, she developed a comprehensive genetics program that included the launch and rapid growth of UCSF’s Adult Genetics and Preventive Genomics Clinic; the expansion of multidisciplinary specialty services in cardiovascular, neurogenetic and cancer genetics; and the implementation of innovative e-consult and telehealth services to improve access to genetic care.

So earned her bachelor’s degree with high distinction in molecular biology and molecular genetics and her medical degree from the University of Toronto. She completed her medical genetics residency at the university’s Hospital for Sick Children and earned her doctorate in molecular genetics from the Max Planck Institute for Molecular Genetics in Berlin and completed a postdoctoral research fellowship in psychiatric genetics at the Centre for Addiction and Mental Health in Toronto.

“I am honored to join Cedars-Sinai as the inaugural chief genomics officer to advance the fields of genetics and genomics with the goal of enhancing patient care and health outcomes,” So said. “Together with our talented team of investigators and clinicians, we will push the boundaries of what is possible in genomic medicine for the benefit of our patients, their families and the wider community.”

So’s current research focuses on optimizing genetic diagnosis and treatment strategies for adults with complex neurodevelopmental, neuropsychiatric and neurological conditions. She also is deeply committed to quality and continuous improvement in the delivery of genetics and genomics clinical services.

“Dr. So’s appointment reinforces our commitment to advancing precision medicine and making leading-edge genomic care accessible to all our patients through all stages of life,” said Ophir Klein, MD, PhD, executive vice dean of Children’s Health and executive director of Guerin Children’s. “We are excited to expand our research and clinical capabilities under her leadership.”

Read more on the Cedars-Sinai Blog: Do Children Need Genetic Testing?

The study is published in the journal Gastroenterology.

“We found that being female, smoking, or having a history of surgeries to treat Crohn’s disease or ulcerative colitis puts patients more at risk for developing other serious inflammatory conditions,” said Talin Haritunians, PhD, co-senior author of the study and an associate professor of Medicine at Cedars-Sinai.

“Genetic variations of IBD, as well as the location of the disease in the gastrointestinal tract, were also associated with developing debilitating extraintestinal manifestations of the disease affecting the eyes, joints, skin, liver and spine,” Haritunians said.

The multi-center study involved over 12,000 subjects: the largest study of extraintestinal manifestations of IBD to date, according to investigators. The scientists looked at patients who had at least one of seven different conditions occurring outside the gut, including psoriasis, inflammation of the eye, and ankylosing spondylitis, a condition which can degrade the spine or hips.

Investigators also identified genetic, clinical and immunological factors associated with primary sclerosing cholangitis—a condition which damages the liver—and with painful peripheral arthritis that affects both the small and large joints of the body.

“These inflammatory manifestations outside the gut impact about 40% of our patients with IBD. The disorders can have a very significant effect on quality of life and, in some instances, are life-threatening. Our findings will help us identify those at risk of developing these related conditions,” said Dermot McGovern, MD, PhD, the corresponding author of the study and director of Translational Research in the Cedars-Sinai F. Widjaja Inflammatory Bowel Disease Institute. 

McGovern expects the findings will also provide a guide to developing novel therapeutic treatments for the other disorders and may also address the underlying gut inflammation.

“Our clinical findings in this study shed light on the risk factors for morbidity associated with IBD. Our genetic findings highlight pathways that are targets for existing drugs or therapeutics in development. These discoveries are critical for developing more personalized approaches to the management of IBD and its various manifestations,” said McGovern, who holds the Joshua L. and Lisa Z. Greer Chair in Inflammatory Bowel Disease Genetics and is the director of Precision Health at Cedars-Sinai.

Other Cedars-Sinai authors involved in the study include Michelle Khrom, Shishir Dube, Gregory J. Botwin, Shaohong Yang, Emebet Mengesha, Dalin Li, Takeo Naito, Nirupama N. Bonthala, Christina Ha, Gil Melmed, Shervin Rabizadeh, Gaurav Syal, Stephan R. Targan Eric Vasiliauskas and David Ziring. Other authors include Millie Long, Lori Robbins, Steven R. Brant, Judy Cho, Richard H. Duerr, John Rioux, Phil Schumm, Mark Silverberg, Ashwin N. Ananthakrishnan, William A. Faubion, Bana Jabri, Sergio A. Lira, Rodney D. Newberry, Robert S. Sandler, Ramnik J. Xavier, Subra Kugathasan, David Hercules and R. Balfour Sartor.

This research was supported in part by the F. Widjaja Foundation Inflammatory Bowel and Immunobiology Research Institute. The Cedars-Sinai MIRIAD IBD Biobank is supported by the F. Widjaja Foundation Inflammatory Bowel and Immunobiology Research Institute, National Institutes of Health/National Institute of Diabetes and Digestive and Kidney Diseases (NIH/NIDDK) grants (P01 DK046763 and U01 DK062413), and The Leona M and Harry B Helmsley Charitable Trust (DPBM and SHARE Consortium).

Conflict of Interest: Dermot McGovern is a consultant for MERCK, Prometheus Biosciences (acquired by MERCK), Takeda and Prometheus Labs.

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Read more in Discoveries Magazine: Ancestry Matters in IBD

This is the future envisioned by Jennifer Van Eyk, PhD, director of the Advanced Clinical Biosystems Research Institute and the Erika J. Glazer Chair in Women’s Heart Health at Cedars-Sinai.

Although the idea of using blood micro-sampling to predict disease has generated much hype in the recent past, Van Eyk’s approach is one that has decades of research behind it.

For the past 25 years, Van Eyk has focused on clinical proteomics, the study of the structure and function of proteins within the body. Today, she is an international leader in the field.

Cells use genes to make proteins that make it possible for the body’s functions to be carried out. By measuring proteins, we can get an accurate view of what our body is doing—and the possibilities are endless, according to Van Eyk.

This year alone, Van Eyk’s work was recognized with the Distinguished Contribution Award from the Association for Mass Spectrometry and Advances in the Clinical Lab, the President’s Distinguished Lecture Award from the International Society for Heart Research, and a spot on the 2023 Ten Years of Impact Power List by The Analytical Scientist.

Van Eyk spoke with the Cedars-Sinai Newsroom about how proteomics is changing medicine now and will continue to in the future.

How do proteins make us unique?

The human genome is not that much different than that of a fly. What makes each of us unique is which of those genes are expressed at any one time—meaning, which proteins are expressed at any one time.

The proteins are the end product. Think of a cell as being a city like L.A. Its DNA is the road map, but the city itself is the proteome, with moving parts and lots of activity.  

After proteins are made, they change. The amount of protein, and the chemical diversity of a protein in any single cell, can quickly change. When you stand up, your proteins change. When you sit down, your proteins change. When you blink your eye, your proteins change. Yet, some proteins can last for years, like the proteins that make up the eye lens.

There are also organ-specific proteins. For example, there are proteins that are only found in the heart. However, the majority of proteins are in all cells, but at different concentrations. What makes them different is chemistry that happens after they are made.

What are you hoping to learn by studying proteins?

Every time a physician has a decision to make, we would like to have a biomarker—a measurable biological substance such as a protein concentration—the physician can base the decision on. If you’re at risk of having sudden cardiac death, we want to have a marker that can tell us you are at risk. If you're coming in with breast cancer, and we want to have a biomarker to know what drug to put you on.

How do you measure proteins?

My lab makes a discovery of something new at least once a month because we can see things and measure things we couldn't before. It's like when you make a cake, you might wonder what difference one teaspoon versus one tablespoon of sugar will make in the final product. Our instruments are so fine we could figure out whether or not you have one more grain of sugar in that teaspoon than you’re supposed to have and what that might mean for a patient.

What do proteins tell us?

Let's say you have a series of alterations to your DNA that puts you at risk of having heart disease. That's informative, but it doesn't tell you when you're going to have a heart attack. It doesn't tell you what degree of hardening of the arteries you already have. Proteins can tell us you're going to have a heart attack, are having a heart attack, have had a change in your calcium level, or a change in your arteries. Proteins tell us what's happening now and predict what is going to happen; whereas genes merely tell us you’re at risk.

Could you give an example?

If you're having a heart attack, your doctor can take a blood sample and measure for a circulating protein that should only be found in the heart. If it’s elevated, it confirms that you’re having a heart attack.  

What are you working on now?

For certain studies, we’re doing remote sampling, something that can be done at home or anywhere and at any time. People mail us blood samples and we analyze the proteins in these samples to determine if their medication is working or if they may be at risk of having a heart attack or stroke, or other health issue. This is a new thing that we're trying to develop, in addition to helping physicians make clinical decisions.

You should be able to know what's going on with your health, even when you're not at the hospital or at your doctor’s office.

Read more in Discoveries: New Tools at the Innovation Center

Alfred E. Mann Charities, Incorporated, has just announced a $25 million gift to the Cedars-Sinai Board of Governors, which marks the organization’s largest single pledge to an individual institution. The gift will establish the Alfred E. Mann Single Cell Precision Medicine Center at Cedars-Sinai, which will accelerate single cell biology research being advanced at the Board of Governors Innovation Center.

“This generous gift will propel groundbreaking research at the innovation center,” said Shlomo Melmed, MB, ChB, executive vice president of Academic Affairs and dean of the Medical Faculty. “Single cell biology is a rapidly growing field in medicine and Cedars-Sinai continues to position itself as an innovative leader in this exciting field, driving clinical innovation for our patients.”

The Mann center will house laboratories where researchers will focus on the causes of developmental, neurological, immunological, cardiovascular, pulmonary and gastrointestinal diseases, as well as develop curative treatments for patients diagnosed with these challenging illnesses.

“What an incredible honor for Cedars-Sinai to receive this unprecedented gift to the Board of Governors,” said Arthur J. Ochoa, JD, senior vice president of Advancement and chief advancement officer at Cedars-Sinai. “The name Alfred Mann characterizes what selfless humanitarianism and scientific brilliance can accomplish.”

This transformative donation also enables the Board of Governors—a community of philanthropic leaders supporting innovation in healthcare—to conclude and celebrate its current $50 million fundraising campaign five years ahead of schedule.

“We are so grateful to Alfred E. Mann Charities for their generous support and for being the catalyst to closing this crucial chapter of the Board of Governors fundraising campaign,” said Jeffrey Golden, MD, vice dean of Research and Graduate Education and director of the Burns and Allen Research Institute at Cedars-Sinai.

Alfred Mann was a prolific inventor who dedicated his life to utilizing technology and innovation to improve health outcomes for millions of people. Some of his most renowned accomplishments include pioneering the development of pacemakers, insulin pumps, inhalable insulin powder, and cochlear implants for the deaf. During his lifetime, he founded 17 companies, all focused on bridging medicine and engineering.

Today, his visionary influence carries on through the work of Mann Charities and its officers and directors, Michael Dreyer and Anoosheh Bostani, valued members of the Board of Governors who are dedicated to facilitating pioneering medical discoveries that result in better treatments and compassionate care of patients. This significant gift from the charitable organization will help to fully realize the shared mission of Mann Charities and Cedars-Sinai.

“There’s no question that this contribution is what Alfred Mann would have envisioned in his unwavering commitment to furthering health care with new and innovative treatments and technologies,” Dreyer said. Bostani added, “As invested Board of Governors members, we look forward to supporting forward-thinking initiatives that will now come to fruition at this new center."

Read more on the Cedars-Sinai Blog: New Tools at the Innovation Center