For instance, regenerating islet-derived protein III (REGIII)β and REGIIIγ are upregulated following administration of the probiotic-derived AHR agonist 1,4-dihydroxy-2-naphthoic acid (DHNA), altering the microbiome and ameliorating dextran sodium sulfate-induced colitis in mice.60 In support of a role for AHR in therapeutic interventions already in use, the increase in Th22 cell differentiation and IL-22 production induced by TNF blockade was abrogated by AHR inhibition in Crohn’s disease (CD) patients treated with antitumor necrosis factor (TNF)-blocking antibodies. Here, AHR is linked to Cowden disease.