What Makes a Scientist Extraordinary? 

by Abigail Glezer

For Dr. Valentina Fossati of the New York Stem Cell Foundation (NYSCF), it’s the ability to bridge cutting-edge research with the profoundly personal realities of living with multiple sclerosis (MS). A kind and brilliant visionary, she approaches science with an almost artistic perspective, referencing an analogy between the brain and an orchestra as she strives to harmonize its complex systems through her work. I had the incredible privilege of interviewing her, and in our conversation, Fossati shared insights on her groundbreaking work on personalized disease models, her holistic approach to studying brain cell interactions, and the deeply personal motivation behind her focus on MS.  

Fossati earned her PhD in stem cell biology from the University of Bologna in 2008, at a time when regenerative medicine was in its infancy. Her skill and passion secured her admission to a specialized course at Cold Spring Harbor Laboratory in the United States, where she learned from leading minds in the field. A mentor she connected with there helped her secure a postdoctoral position at the Mount Sinai School of Medicine in New York City, where she worked with induced pluripotent stem cells (iPSCs)—a revolutionary technology enabling scientists to model diseases using patient-derived cells. Reflecting on the field’s evolution, she says, “I’ve followed the stem cell field from the very beginning, and I’m still amazed by the opportunities it offers. It’s like science fiction becoming real.” 

Fossati’s path then crossed with Susan Solomon, the CEO of NYSCF at the time, who recognized her talent and drive and offered her the opportunity to run her own lab. But just as her dreams of becoming an independent researcher became a reality, Fossati was diagnosed with MS, a chronic disease of the central nervous system that attacks myelin, the protective covering of nerves. 

“At the time of my diagnosis, I thought about quitting everything—science, New York—but then I decided to channel my fear into something meaningful,” she recalls. “I told myself, ‘If I continue working in science, I want to work on something that I care about.’” With this determination, Fossati approached Solomon and proposed a bold new focus for her research: the brain and MS. “I’ve always been terrified of the brain, but my MS diagnosis pushed me to study it more deeply. It became personal.” 

Fast-forward 12 years, and Fossati’s work has truly contributed to the revolution of neuroscience and regenerative medicine. She has pioneered methods to convert patient stem cells into all major brain cell types, including astrocytes, oligodendrocytes, and microglia—essential components implicated in neurodegeneration. She leads efforts to develop three-dimensional “mini-brain” organoids and generated the first iPSC lines from people with progressive MS. Her research has even reached the International Space Station to study the effects of microgravity on the central nervous system. 

“When you’re diagnosed with MS in your 30s, you have so many questions. Will I still have a career? A family?” she shares. These personal questions continue to drive her research and her belief in the importance of patient-centric science. She regularly speaks with MS patients who share their struggles with existing treatments, which further fuels her motivation. “I’ve seen how hard MS treatments can be. As a patient, I know what it’s like, and that perspective drives my work.” Fossati’s research goals center on creating personalized disease models from patient-derived cells as the future direction for MS. “I’ve always been fascinated by the idea of studying diseases using patient cells. It’s personal, it’s relevant, and it’s the future.”  

Her approach to her work also reflects a belief in interconnectedness—both in how brain cells work together and in the collaborative nature of science itself. “The brain is like an orchestra, as my colleague and friend Dr. Shane Liddelow once said. Every player has to be in sync. If one is out of tune, the entire system is affected.” One of Fossati’s key breakthroughs is developing protocols to differentiate stem cells into multiple significant brain cell types. She leverages them to address a long-standing limitation in neuroscience—studies often focus on isolated cell types, reducing the ability to understand the complexities of disease. “If you want to protect neurons, you first protect the oligodendrocytes and the myelin. Yet these have been largely neglected for years in favor of just focusing on the neuron.” Having the ability to study a myriad of cell types alongside each other, noting interactions and specific relationships, provides more comprehensive and encompassing insight that drives research forward. She sees this philosophy extending to the scientific community as well, advocating for collaboration across disciplines. “I believe in collaboration across disciplines because no one lab or person can solve these complex problems alone.” 

Continuing from the earlier conversation about her research goals, Fossati envisions a future where human-cell-based models are indispensable tools in the fight against neurological diseases. “They don’t replace traditional approaches but complement them, answering questions animal models can’t,” she explains. Her work underscores the importance of these models in creating more personalized approaches to medicine, “ones that help us predict how a disease will progress in an individual and guide the best treatments for them.” This vision relies on the collaboration of knowledge across disciplines. As she puts it, “The next breakthroughs will come from integrating knowledge across fields—neuroscience, biochemistry, genetics—and developing models that reflect the real complexity of human biology.”  

 Ultimately, Fossati’s dream is to push beyond halting diseases, and instead striving to reverse their damage. But even if we look at her accomplishments as of today, she stands as a remarkable example of resilience and innovation, using her personal journey and scientific brilliance to drive transformative advancements in regenerative medicine and inspire the next generation of scientists, myself included.