The results showed that PHPO+ cisplatin suppressed the anti-apoptotic factors Bcl-xL, Bcl-2 and XIAP, but activated the pro-apoptotic factors Bad, Bax, caspase 9, caspase 8, caspase 7 and PARP though inhibiting the PI3K/Akt, MAPK, ATM/Chk2 pathways in both chemosensitive and chemoresistant ovarian cancer cell lines. The gene discussed is CASP9; the disease is ovarian carcinoma.