To address the role of ATF2 in de novo melanoma formation Tyr::CreER::NrasQ61K::Ink4a−/− (KO of exon 2–3 of Cdkn2a locus, which encodes for both p16Ink4a and p19Arf; [38]) mice, which develop spontaneous melanoma (Lynda Chin, unpublished observations), were crossed with Atf2md mice. The gene discussed is CDKN2A; the disease is melanoma.