The Cdk4::NRAS model we used is a well-characterized model of UVR-induced MM, and in terms of an acceleration of MM onset after neonatal UVR it behaves similarly to other models which carry constitutive oncogenic mutations in melanocytes (e.g. the Mt-Hgf model) (Noonan et al., 2001). The gene discussed is CDK4; the disease is Miyoshi myopathy.