In summing up, the main mechanism by which Gal-3 regulates immunosuppressive capacity of regulatory DCs in the gut is relied on the TLR-4-dependent activation of IDO-1/KYN pathway and consequent expansion of colon-infiltrated Tregs which suppress Th1 and Th17 cell-driven colon inflammation (Figure 10). This evidence concerns the gene IDO1 and colitis.