The major interest of our lab is to study NADPH oxidase as a critical regulator of inflammation and host defense. NADPH oxidase is an emergency host defense pathway that is rapidly activated in response to certain microbial products, and converts molecular oxygen to superoxide anion and downstream reactive oxidant intermediates (ROIs). Chronic granulomatous disease (CGD) is an inherited disorder of the NADPH oxidase characterized by severe bacterial and fungal infections (e.g., invasive aspergillosis) and by excessive inflammation. In addition to its critical host defense role, our lab, in collaboration with colleagues, found that NADPH oxidase also functions to restrain inflammation by modulating redox-sensitive innate immune pathways. We have established several tools to evaluate innate immune responses in vivo using genetically engineered mice in clinically relevant models of infection, inflammation, and lung injury. We are also conducting studies to evaluate the role of NADPH oxidase and its regulated pathways in shaping the tumor microenvironment.