Cisplatin is considered as a type of alkylating agent and one of the most effective drugs used to treat cancers.11, 31 BER and HR reportedly repair the DNA damages induced by cisplatin.32 MMS is also an alkylating agent and induces single‐strand breaks, which is repaired by XRCC1‐dependent BER.33, 34 Camptothecin is a topoisomerase I inhibitor acting to induce DNA breaks. This evidence concerns the gene XRCC1 and cancer.