XRCC1 and cancer: There are also some contradictory reports such as that of Mort et al(20), who reported no correlation between CRC risk and polymorphisms in any of the 4 NER genes or in XRCC1. Yeh et al(21) investigated the involvement of the DNA repair pathway genes in modulating the risk of CRC in a Taiwanese population and found the Arg 399 form to cause an increased cancer risk.