PIK3CA and ovarian cancer: Further work suggested that paclitaxel induces the phosphorylation of BAD Ser-112 via the Erk cascade, and the phosphorylation of both BAD Ser-136 and Raf-1 Ser-259 via the PI3K/Akt cascade, and that inhibition of either of these cascades sensitizes ovarian cancer cells to paclitaxel [425].