1. Department of Gastroenterology, Longgang People's Hospital, Shenzhen, Guangdong 518172, P.R. China
2. Department of Pathology, The First People's Hospital of Xinxiang City, Xinxiang, Henan 453100, P.R. China
3. Department of Oncology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi 341000, P.R. China