PIK3CA and prostate cancer: The NVP-BEZ235 (PI3K/mTOR inhibitor) was effective in suppressing the CSCs and growth of prostate cancer.136 The hyperactivation of the PI3K/Akt/mTOR pathway was linked with the upregulation of CXCR4 in A549 gefitinib-resistant (A549-GR) lung cancer cells.