Valentina Greco, PhD

Valentina Greco was born in Palermo, Italy and earned her undergraduate degree in Molecular Biology at the University of Palermo, Italy (1996). She earned her PhD at the EMBL/MPI-CBG, Germany (1998-2002), her postdoc at the Rockefeller University (2003-2009) and is currently a Professor in the Genetics, Cell Biology and Dermatology Departments, a member of the Yale Stem Cell Center and Yale Cancer Center at Yale University (2009-present) and a Howard Hughes Medical Institute (HHMI) Investigator (2024-present).

The goal of my laboratory is to discover the fundamental principles of organ regeneration during homeostasis and how pathology emerges from normal tissue growth. A major challenge in the mammalian stem cell field was the inability to follow the same cells in vivo. This limitation obscured insight into the dynamics of these processes, the contributions of intercellular interactions to tissue growth, and the initial events leading to malignancy. To overcome this challenge, my lab established, for the first time, the ability to visualize skin epithelial stem cells and their behaviors in an intact animal by two-photon microscopy. We understand these cell behaviors as expression of the architectures and principles that govern the tissues these cells inhabit much like human behaviors are an expression of the systems and structures in which they are embedded (e.g. a lab, an organization). Looking at the skin epithelium, we have studied regeneration in real-time by labeling and tracking stem cells and the different tissue types that surround them. To address their functional roles, we manipulate cells and their behaviors by altering key signaling pathways and studying the consequences to identify the critical cellular and signaling components for the regenerative process. Our work addresses the fundamental principles used by homeostatic processes, which will provide critical knowledge that will lay the foundation to later address the cellular mechanisms that go awry during disease states such as cancer. This novel live imaging approach has repeatedly led us to a significant number of breakthroughs that neither we nor the field could have anticipated, including but not limited to 1) stem cell position dictates their fate in the hair follicle, 2) a stem cell-mediated phagocytic clearance mechanism that regulates the size of the hair follicle stem cell pool and 3) the unanticipated plasticity of the skin epithelium to correct aberrant tissue growths induced by mutational and non-mutational insults.

Dr. Greco has been the recipient of many awards over her career, such as being recently inducted to the American Academy of Arts and Sciences in 2025, named HHMI Investigator in 2024, elected Fellow for the American Society for Cell Biology (ASCB) in 2024, co-awarded an European Research Council (ERC) Synergy grant in 2024 and recognized as one of "50 Scientists that Inspire" by Cell Press on its 50th Anniversary.