ACTB and melanoma: Briefly, when G12VKras was overexpressed in melanocytes in mice using the β-actin promoter (β-actin:LSL:G12VKras; Meuwissen et al., 2001), it induced rapid onset melanoma (median time to onset 2 months, 100% penetrance within 3 months) in the absence of D594ABraf (manuscript submitted).