AHR and hypertensive disorder: Since several uremic toxins from the kynurenine and indole pathways are endogenous ligands of AhR [58] and previous studies reporting maternal exposure to exogenous AhR ligand can induce hypertension and kidney disease in adult offspring [59,60], AhR activation might be an important target hub linking tryptophan metabolism and hypertension and kidney disease of developmental origin.