NOS2, also named as iNOS and NOS2A, produces nitric oxide (NO) which is a messenger molecule with diverse functions throughout the body. NO is a reactive free radical which acts as a biologic mediator in several processes, including neurotransmission, antimicrobial and antitumoral activities. NOS2 is a nitric oxide synthase which is expressed in liver and is inducible by a combination of lipopolysaccharide and certain cytokines. iNOS has a very short half-life due to rapid degradation by calpain. iNOS monomer is a direct substrate of calpain I and can be cleaved by calpain I at the canonical CaM-binding site(503-532aa) of iNOS, and then a ~70kD band can be detected by western. This antibody is specific to NOS2.