T cells are vital to host defense against pathogens. On the other hand, inappropriate T cell activation can also cause problems such as allergic disease or autoimmune disease. Our laboratory studies the regulation of T cell effector functions in host defense and allergic disease. Starting in humans, we employ discovery-based approaches such as RNA-Seq and mass spectrometry to drill down to the molecular level, with the goal of developing new therapies to modulate T cell function in disease.