Alopecia phenotype in Tmprss6−/− mice. (A) Representative photographs of 4-week-old Tmprss6+/+ and Tmprss6−/− littermate mice. (B) Skin sections from 4-week-old wild-type and Tmprss6−/− mice showing dystrophic hair follicles and hyperkeratosis in Tmprss6-null tissue, compared with the wild-type. Bar represents 100 μm; magnification, 20×/0.40 NA.