MTOR and cancer: To determine whether the effect of PP242 on decreasing FLIPS is indeed due to inhibition of mTOR, we further tested other mTOR inhibitors and found that both INK128 (an mTOR kinase inhibitor) and BEZ235 (an PI3K/mTOR dual inhibitor), but not rapamycin (an allosteric mTOR inhibitor), decreased FLIPS levels and enhanced TRAIL-induced killing of cancer cells.