Colon or rectal (colorectal) cancer (CRC) is one of the leading causes of cancer‐related mortality,1 and the worldwide incidence and death rates have increased, especially in developing countries.2 Multiple gene mutations have been reported in patients with CRC, especially, KRAS mutations are detected in approximately 40% of patients,3 whereas NRAS and BRAF mutations are less common.4, 5 In addition to surgical resection and radiotherapy, chemotherapy and molecular target therapy are used in CRC. This evidence concerns the gene KRAS and colorectal cancer.