PTEN and melanoma: PAX3 expression is controlled in melanoma by PI3K signaling (Bonvin et al. 2012), which has been implicated in both melanomagenesis and senescence bypass through inactivation or loss of PTEN, an inhibitor of PI3K, or via activating mutations in PI3K itself (Dankort et al. 2009; Madhunapantula and Robertson 2009; Cao et al. 2013; Marsh Durban et al. 2013).