Data extraction
All data sources were extracted from the hospital’s medical record management system. Keywords, including ”lymphocyte proliferative diseases after transplantation” and ”liver transplantation”, were used to search the database. The collected indicators included: the (1) basic information: gender, primary disease, age at transplantation, and weight, among others; (2) laboratory indicators: blood test (WBC, HBG, NE, PLT), liver and kidney function (ALT, AST, TBIL, DBIL, ALB, AKP, γ-GGT, CREA, BUN), blood glucose (GLU), coagulation function (PT, INR), blood lipids (TG, CHOL), and tacrolimus concentration; (3) transplantation-related indicators: transplantation method, graft weight, graft/weight ratio, intraoperative blood loss, and blood type; (4) viral infection: pre-operative EBV and cytomegalovirus (CMV) infections, time interval between surgery, and the first EBV/CMV infection; (5) donor information: blood type, pre-operative EBV, and CMV infection, among others.