1. Department of Hematology, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
2. Department of Oncology, Qinghai Provincial People's Hospital, Xining, Qinghai 810000, P.R. China
3. Department of Hematology, The First People's Hospital of Yulin, Yulin, Shaanxi 719000, P.R. China