PTEN and neoplasm: Consistent with this, RIOK2overexpression; Pten−/−; Ink4a/arf−/− astrocytes displayed increased phosphorylation of Akt at Serine-473 (Figure 4C), and tumor tissue from RIOK2overexpression; Pten−/−; Ink4a/arf−/− cells showed specific staining for Akt-Ser473-P (Figure 4D).