Copper blue protein is mainly used clinically to assist in the diagnosis of certain diseases related to the liver and bile. Also called copper oxidase, the main role of copper blue protein is to regulate the distribution of copper in various organs and tissues of the body, and to synthesize enzymatic proteins containing copper in the human liver, copper blue protein has the role of an antioxidant. Clinically, copper blue protein test can be used to assist in the diagnosis of the presence of bean nucleus degeneration in the liver. When the liver has bean nucleus degeneration, the value of copper blue protein test will be significantly lower than the normal value, and copper blue protein test can be used clinically to assist in the detection of chronic hepatitis. When hepatitis is present, the value of copper cyan protein is abnormal, and copper cyan protein is used clinically to assist in the diagnosis of primary liver cancer and cirrhosis. With both of these diseases, the copper cyan protein test will be significantly higher than normal. The copper cyan protein test can be used clinically to assist in the diagnosis of certain kidney-related diseases, such as nephrotic syndrome.