PTEN and melanoma: PTEN loss of function mutations activate the PI3K-AKT pathway, are frequently detected in cutaneous melanoma6, cooperate with mutant BRAF or NRAS to drive melanomagenesis40, 41, and accelerate primary tumor growth in genetically engineered Dct::TVA, BrafV600E; Cdkn2aflox/flox murine melanoma models induced in epidermal melanocytes of the ear pinnae42.