p16 induction led to delayed growth of hair follicles (HF), reduced hair-follicle stem cell (HFSC) proliferation, and the formation of deformed HFs during the anagen stage initiated at 3 weeks of age (Fig. 1k and Supplementary Fig. 1f, g), reminiscent of the effect of p14ARF activation33. The gene discussed is CDKN2A; the disease is hydrops fetalis.