AHR and kidney disorder: Considering the regulatory influence of AHR on both Treg and TH17 cells [52], and the participation of several microbial tryptophan catabolites as AHR ligands in the developmental programming of kidney disease and hypertension [155], further investigation is warranted to comprehensively understand the protective role of tryptophan metabolites and IDO inhibitors in modulating CKM syndrome of developmental origin.