Our recent study indicates that AHR activation by ketoconazole, a potent AHR ligand,20 upregulates OVOL1 in NHEKs.18 Therefore, we hypothesized that AHR upregulates FLG via OVOL1 and that OVOL1 impairment is involved in FLG downregulation, which may possibly contribute to the development of AD. Here, OVOL1 is linked to Alzheimer disease.