PTEN and melanoma: The degree of Akt pathway activation in melanoma cells with Phd2 deletion is less than that in melanoma cells with Pten deletion, which may be one of the reasons that melanoma has a longer latency in Tyr::CreER; BrafV600E; Phd2−/− mice than that in the Tyr::CreER; BrafV600E; Pten−/− mice.