XPA and neoplasm: Despite the association of p53 and MMR defects with cisplatin resistance, RNAi against CSB and XPA in this panel of tumour cell lines deficient in p53 (PC-3, DU145 and HCT116p53-/-) and MMR (PC-3, DU145, HCT116 and HCT116p53-/-) resulted in a significant increase in the sensitivity of cells to cisplatin-induced cell death.