RAC2 is a small signaling G protein/GTPase which is part of the RAS superfamily of small GTP-binding proteins which regulate cell growth, actin cytoskeletal organization, cell proliferation, survival, cell cycle progression, gene transcription rgulation and the activation of protein kinases. RAC2 cycles between an active gtp-bound and inactive gdp-bound state. In active state, RAC2 binds to a variety of effector proteins to regulate cellular responses, such as secretory processes, phagocytose of apoptotic cells and epithelial cell polarization. RAC2 is involved in the regulation of the nadph oxidase.