ITPA and cytomegalovirus pneumonia: A total of 5 patients relapsed in the ITPA variant group (BM = 1, CNS = 1, testis = 1, BM and CNS = 1, and BM and testis = 1), and 2 patients among them died due to transplantation-related complications (veno-occlusive disease, cytomegalovirus pneumonia).