In addition to the AD-like symptoms, which result from the epidermal abnormalities, K5-R1/R2 mice develop progressive hair loss, because activation of Fgfr2 by Fgf7 and Fgf10 is required for hair follicle stem cell proliferation and thus for hair regeneration in mice (Greco et al., 2009; Yang et al., 2010). This evidence concerns the gene KRT5 and Alzheimer disease.