In the paper entitled “Protein kinase Cε, which is linked to ultraviolet radiation-induced development of squamous cell carcinomas, stimulates rapid turnover of adult hair follicle stem cells,” A. Singh et al. report that protein kinase C epsilon (PKCε), a member of the protein kinase C superfamily, plays a critical step in the development of cutaneous SCC induced by repeated exposures to ultraviolet radiation (UV). This evidence concerns the gene PRKCE and squamous cell carcinoma.