AHR and colitis: For example, 2-(1' H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE), an endogenous Ahr ligand, ameliorates autoimmune inflammation by inducing Treg cells and reducing proinflammatory cytokine levels and the macrophage frequency in experimental models of colitis [13] and uveoretinitis [15].