AHR and Alzheimer disease: It is reported that SIRT1 promotes the activation of AhR, in turn, enhanced AhR induces FLG expression via OVOL1 in normal human epidermal keratinocytes, suggesting AhR-OVOL1-FLG axis is a potent target for treatment of AD (Mulero-Navarro and Fernandez-Salguero, 2016; Tsuji et al., 2017).