NOS2 and rheumatoid arthritis: NF-κB regulates the expression of many genes that are involved in inflammatory responses, including TNF-α, IL-1β, IL-6, CCL2, CCL5, MMP-3, ICAM-1, VCAM-1, inducible nitric oxide synthase, and cyclo-oxygenase-2, all of which are known to participate in the pathogenesis of RA.