Julio A. Aguirre-Ghiso, PhD, is an Endowed Mount Sinai Professor of Cancer Biology and co-Leader of the Cancer Mechanisms Program at The Tisch Cancer Institute, and Director of Head and Neck Cancer Basic Research in the Department of Otolaryngology. He is also a member of the Precision Immunology Institute and the Black Family Stem Cell Institute, both at Mount Sinai. He also serves as President Elect of the Metastasis Research Society. His work focuses on understanding the biology of residual cancer cells that persist in a dormant state after initial therapy. His research team led, along with others, a paradigm shift, revealing novel cancer biology that diverges from the notion that cancer is perpetually proliferating. His team discovered that reciprocal crosstalk between disseminated tumor cells and the microenvironment regulates the inter-conversion between dormancy and proliferation of metastasis.