In contrast, results obtained in ovarian cancer cell lines demonstrated that TP53(–/–) cells responded most sensitively to cisplatin (Hagopian et al., 1999; Pestell et al., 2000), while in mouse testicular teratocarcinoma cells cisplatin treatment resulted in rapid apoptosis in Trp53(+/+) cells but not in Trp53(–/–) cells (Zamble et al., 1998). The gene discussed is TP53; the disease is ovarian cancer.