1 Department of Hematology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China.
2 Division of Gastroenterology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
3 Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
4 Department of Hematology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China. hanbing_li@sina.com.