CLDN1 and Alzheimer disease: FLG; LOR; PSORS1C2; sciellin; LCE genes were not downregulated in AD skin lesions compared to healthy skin and FLG breakdown products such as UCA1; UROC1; OPLAH; GGCT; ARG; CASP14; TYR were comparable between AD and healthy skin.Significant downregulation of tight junction genes such as CLDN1; CLDN8; CLDN10 and adherens junction genes CDH10; CDH12; CDH19; CDH20 and keratin genes KRT33A; KRT77; KRT79Significant downregulation of lipid metabolism genes HAO2; ELOVL3; GAL; FAR2; AWAT1; DGAT2; FABP7; FADS1 and 2.