Importantly, the genomic instability caused by three different drugs (camptothecin [33], a topoisomerase inhibitor; 5-fluorouracil, a thymidylate synthase inhibitor; and paclitaxel, an antimicrotubule agent), which induce DNA breaks by different mechanisms, was minimized by addition of RAD51 inhibitor in cell lines representing three different cancers (EAC, colon and breast). This evidence concerns the gene TYMS and cancer.