Aging is a major risk factor for a number of diseases, including neurodegenerative diseases, diabetes, and cancer. However, the mechanisms responsible for aging remain poorly understood. Work from our lab and others has linked a particular family of proteins, known as FOXOs, to healthy aging in various species, including humans. The goal of this project is to understand how the different FOXO family members contribute to cellular maintenance in humans. Understanding the complex interplay between the different FOXOs will significantly advance our understanding of why cell and tissue function declines with age, and in the long term may lead to strategies to combat age-related diseases.