TNF and colitis: Interestingly, the administration of MMF in mice with TNBS-induced colitis led to a profound decrease in the levels of IFN-γ, TNF-α, IL-12, IL-6, and IL-1β in the serum and colon tissues at days 3 and 10, while the mRNA expression levels of IFN-γ and IL-1β were markedly upregulated in colitic mice that were treated with MMF (i.p. or gavage, 2 mg) but not in those that were treated with 1 mg of MMF.