PTEN and hamartoma: In P21 untreated Pten cKO retinas, pS6 expression was elevated in both peripheral and hamartoma regions of the retina compared to wild-type controls (Fig. 7D,D′), consistent with our previous study (Cantrup et al., 2012) and confirmed by western blotting (n=4; 3.94±0.37 normalized pS6 protein levels, P<0.01; Fig. 7F,G).