We observed pAKT expression and increased proliferation in follicular McSCs (Supplementary Fig. 3g–i) similar to c-Kit-CreER:Braf:Pten McSCs (Fig. 2b, c), with progression of epidermal oncogenic Mcs into epidermal melanoma cells that was never observed in control mice (Fig. 2h; Supplementary Fig. 3j). The gene discussed is PTEN; the disease is melanoma.