TNF and myocarditis: Owing to their potent anti-inflammatory activity, decreased intestinal IL-10 and intestinal IL-10+ Treg led to increased intestinal IFN-γ+ T cell response, which contributed to viral restriction in the intestine first, then blood and heart, eventually resulting in mitigated myocarditis as well as reduced cardiac cytokine production (TNF-α, IL-1β, IL-6, Figure 3B).