1. Centre for Liver Disease, 458th Hospital of People's Liberation Army, Guangzhou, Guangdong 510602, P.R. China
2. Department of Respiration Medicine, Zhujiang Hospital, Guangzhou, Guangdong 510282, P.R. China
3. Clinical Laboratory, Nanshan Maternity & Child Healthcare Hospital, Shenzhen, Guangdong 518067, P.R. China