CRC is a representative tumor characterized by the accumulation of mutations, including the activation of oncogenes, such as KRAS, MYC, and EGFR; the inactivation of anti-cancer genes, such as APC, DCC, and TP53; mutations in mismatch repair genes, such as MLH1, MSH2, PMS1, and PMS2; and the overexpression genes such as PTGS2 and CD44 (13). The gene discussed is KRAS; the disease is cancer.