PP242 is an inhibitor at the kinase domain of the mammalian target of rapamycin (mTOR), which is a Ser/Thr kinase and a cell growth controller. PP242 inhibits mTORC1 more effectively than rapamycin. Unlike rapamycin, PP242 inhibits both mTORC1 and mTORC2 with IC50 values of 0.03 and 0.058 µM, respectively and it can inhibit cap-dependent translation. PP242 functions by blocking the phosphorylation of Akt at S473 and preventing mTOR activation. PP242 exhitibits IC50 values for other kinases of 0.11 µM (JAK2), 0.41 µM (DNAPK), 0.05 µM (PKC?), 0.2 µM (PKCβ I and II), 4.4 µM (EGFR), and1.5 µM (VEGFR2).