Since TPT is used as therapy for recurrent cisplatin resistant and refractory ovarian cancer, and increased expression levels of CHEK1 are observed in ovarian cancers, we hypothesized that inhibiting CHEK1 could be a means to enhance the anti-cancer activity of TPT preferentially in ovarian cancer cells, thus increasing their therapeutic index in cancer cells as compared to normal tissues. This evidence concerns the gene CHEK1 and ovarian carcinoma.