CDKN2A and melanoma: However, this is not a universal effect of Cry mutation: Ink4a−/−,ras(V12G) tumor suppressor/oncogene mutant mice develop melanomas with 100% incidence with light exposed areas, and the combination of Ink4a−/−,ras(V12G),Cry1/2−/− did not affect melanoma incidence or survival (31), indicating that the antitumorigeneic effect of the Cry mutation is context-dependent.