NOS2 and colitis: In animal models of colitis, MSC application efficiently reduces T helper 1 and T helper 17 responses and downregulates pro-inflammatory cytokines (such as tumour necrosis factor alpha (TNF-α), interleukin (IL)-1β, IL-6, IL-17, inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and interferon gamma (IFN-γ) while enhancing the numbers of regulatory T cells and upregulating anti-inflammatory cytokines (such as IL-10) [112–115].