All study subjects were enrolled at 302 military hospital, Beijing, China, and were followed up during the study period of 36 months, until confirming HCC diagnosis or the date of study end (December 31, 2016). The study population included any hepatic cirrhosis patients over 30 years old who were identified as HBV or HCV infected patients for at least 5 years. Some patients with the following conditions were excluded: patients who were diagnosed with HCC at starting point of this study; patients with other systemic disease such as diabetes and hypertension; patients after surgery, interventional therapy, radiotherapy, chemotherapy, and other invasive treatment; patients suffering from severe complications such as upper gastrointestinal bleeding and hepatic encephalopathy. The final diagnosis was made by liver histopathology or MRI based on guidelines from Ministry of Health of the People's Republic of China  and guideline from the Chinese Society of Hepatology and the Chinese Society of Infectious Diseases [13, 14]. The study procedures were approved by the ethics committee of the 302 Military Hospital of China and written informed consent was obtained from each subject.