By affecting FLG mRNA expression, the production of functional filaggrin monomers and their degradation at the enzymatic level of processing, IL-17A affects, in particular, responses to inflammation, epidermal differentiation, stratum corneum formation and stress, and chemotaxis, and the G/G genotype in IL-17A (rs2275913), together with coexisting mutations in the 2282del4 FLG gene, increases the incidence of AD by 9-fold [41]. Here, IL17A is linked to Alzheimer disease.