NOS2 and inflammatory bowel disease: In the early stage of IBD, a number of proinflammatory molecules such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin-4 (IL-4), IL6, IL-1β and tumor necrosis factor-alpha (TNF-α), have been implicated to play crucial roles in mediating immune inflammatory responses16.