Preclinical trials have suggested that the KRAS mutation would confer resistance to radiotherapy in rectal cancer,15,16 while there have been clinical analyses finding that the KRAS mutation did not predict the clinical efficacy of neoadjuvant CRT in rectal cancer.4,8 The role of the KRAS oncogene is unclear in rectal caner patients who received preoperative CRT and curative surgery,17,18 and clinical studies for this subject are scarce in the Asian population. Here, KRAS is linked to rectal cancer.