PTEN and neoplasm: To elucidate mechanisms underlying melanomagenesis in Tyr::CreER; BrafV600E; Phd2−/− mice, we first studied gene expression in haplo-deficient and homozygous Phd2-depleted mouse tumor tissues in comparison to that in Tyr::CreER; BRafV600E; Pten−/− mice by quantitative reverse transcription PCR (RT-PCR).