Immunity-related GTPase family M protein, also known as IRGM, is required for clearance of acute protozoan and bacterial infections. This protein functions in innate immune response probably through regulation of autophagy. It may regulate proinflammatory cytokine production and prevent endotoxemia upon infection and may also play a role in macrophages adhesion and motility. Recombinant human IRGM protein, fused to His-tag at Nterminus, was expressed in E.coli.