Small molecules utilized in the screen were all obtained from the Molecular Screening Facility at The Wistar Institute. GSK126 was obtained from Xcess Biosciences and Active Biochem. UNC1999 was obtained from Selleckchem. The following antibodies from the indicated suppliers were used: anti-EZH2 (BD Bioscience, Cat. No: 612666, 1:1000), anti-EZH2 (Cell Signaling, Cat. No: 5246, 1:100), anti-ARID1A (Sigma, Cat. No: HPA005456, 1:1000), anti-H3K27Me3 (Cell Signaling, Cat. No: 9733, 1:1000), anti-β-actin (Sigma, Cat. No: A5441, 1:10,000), anti-ARID1A (Santa Cruz, Cat. No: sc-32761, 1:500), anti-Ki67 (Cell Signaling, Cat. No: 9449, 1:1000), anti-PIK3IP1 (Santa Cruz, Cat. No: sc-86785, 1:500), anti-Histone H3 (Millipore, Cat. No: 06-755, 1:1000), anti-GAPDH (Millipore, Cat. No: MAB374, 1:10,000), anti-cleaved caspase 3 (Cell Signaling, Cat. No: 9661, 1:10,000), anti-PI3K (p110alpha) (Cell Signaling, Cat. No: 4255, 1:1000), anti-pAKT (T308, Cell Signaling, Cat. No: 13038, 1:1000), anti-AKT (Cell Signaling, Cat. No: 9272, 1:1000) and anti-H3K9Me3 (Abcam, Cat. No: ab8898, 1:1000). pBabe-Myr-PIK3CA143V plasmid was obtained from Addgene. pBabe-EZH2, pBabe-EZH2 ΔSET and pQCXIP-PIK3IP1 plasmids were generated by standard molecular cloning protocols, and details are available upon request. Growth factor reduced Matrigel was purchased from BD Bioscience.