AHR and skin infection: They can be produced by Malassezia metabolism.91,92 Indole compounds are robust ligands and agonists of the aryl hydrogen receptor (AhR), and they are associated with skin carcinogenesis.93 Abundant AhR, malassezin, and indoles can be observed in M. furfur yeast strains causing skin infections, and is related to disrupted TLR-associated dendritic cell maturation.92 Kynurenine, a key oncometabolite in the tryptophan pathway linked to numerous diseases, serves as a ligand activating AhR in cells.