NOS2 and infectious otitis media: The mechanism(s) by which dietary cimetidine and clobenpropit significantly inhibit AOM/DSS-induced colorectal carcinogenesis include modulation of proliferation, apoptosis, the mRNA expression of two inflammatory enzymes (COX-2 and iNOS) and several cytokines (TNF-α, IL1β and IL-6), oxidative stress and the antioxidant status.