The NRAS mutation is found in several cancers such as melanoma (13 ~ 25%), colorectal cancer (1 ~ 6%), lung cancer (1%), thyroid cancer (7%) and hepatocellular carcinoma (10%). It is known that the response to colorectal cancer drug such as Erbitux and Cetuximab decreased and the prognosis of the patient with metastatic colorectal cancer is poor if the patient has NRAS mutation.