CLDN1 and Alzheimer disease: Ex vivo skin barrier integrity was evaluated using electrical impedance spectroscopy (EIS), RNA-sequencing, and untargeted proteomics, complemented by analyses of skin biopsies from dupilumab-treated AD patients.<h4>Results</h4>Spatial transcriptomics demonstrated that AD lesions showed reduced expression of key barrier genes, including CLDN1, FLG, and FLG2.