Some studies have been reported that rectal cancer with the KRAS mutation is likely to have poor response to preoperative CRT compared with wild-type tumors.12,27 However, in the meta-analysis by Clancy et al,28 there were no significant differences in tumor response between the wild-type and mutant-type KRAS groups, irrespective of the chemotherapy regimen. Here, KRAS is linked to rectal cancer.