Valter D. Longo is an Italian-American biogerontologist and cell biologist known for his studies on the role of fasting and nutrient response genes on cellular protection aging and diseases and for proposing that longevity is regulated by similar genes and mechanisms in many eukaryotes. He is currently a professor at the USC Davis School of Gerontology with a joint appointment in the department of Biological Sciences as well as serving as the director of the USC Longevity Institute.