Metabolism is the set of biochemical reactions that occur within cells to sustain life. As such, metabolism, by definition, remains the single most fundamental force driving cell fate. Given the critical nature of T cells in clearing and controlling infections and cancer, as well as mediating protective immunity over the long-term, it is logical that a considerable effort is made to target these cells for therapeutic purposes. However, while metabolism regulates the fate and function of T cells, or of any immune cell for that matter, metabolic interventions for manipulating immunity are rare and can be considered a largely untapped opportunity. Our research is focused on establishing fundamental mechanisms of metabolic regulation in T cells, with a view toward identifying new ways to regulate immune cell function through the manipulation of metabolic pathways. Underlying mechanisms of how T cell metabolism and function is altered in the tumor microenvironment will be discussed.