NOS2 A gene on chromosome 17q11.2-q12 that encodes inducible nitric oxide synthase (iNOS), a small molecule that has various roles in cellular functions and acts via a cGMP-mediated signal transduction pathway. iNOS is both tumouricidal and bactericidal, has nitrosylase activity, and mediates cysteine S-nitrosylation of cytoplasmic target proteins such COX2. It is regulated by calcium/calmodulin, induced by endotoxins and cytokines, including IFN-gamma, in synergy with bacterial lipopolysaccharides (LPS, TNF or IL1B/IL-1 beta). Aspirin inhibits its expression and function. Some genetic variants of NOS2 play a role in resistance to malaria. NOS2 is also a less preferred gene symbol for what is now designated as NANOS2, see there.