AHR and Alzheimer disease: To investigate whether an overlap exists between AHR target genes and genes regulated in AD keratinocytes, we compared DEGs from all keratinocytes (clusters KC1 through KC3) of patients with AD [lesional AD vs. healthy controls from GSE147424 and He et al. 2020 (17), referred to here as “AD transcriptome”] with DEGs from our analysis of HaCaT cells treated with an endogenous AHR ligand, FICZ, for 24 h (FICZ vs. control, referred to here as “AHR transcriptome”) (Figure 3).