ARG1 and colitis: Our study results proved that the levels and expression of pro-inflammatory factors (TNF-α, IL-6, and IL-1β) and anti-inflammatory factors (IL-10, Arg-1, and TGF-β1) significantly increased in serum and colonic tissues after colitis was induced by DSS in mice, which is content with the changes in M1/M2 macrophage expression and relative M1/M2 ratios.