1. Department of Pathology, The Sixth Affiliated Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510655, P.R. China
2. Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, Guangdong Institute of Gastroenterology, The Sixth Affiliated Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510655, P.R. China
3. Department of Pathology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong 510080, P.R. China