Inclusion Criteria:  Receiving kidney transplantation in West China Hospital, Sichuan University  Exclusion Criteria:  1) History of rejection or infection over the previous 3 months; 2) receiving kidney transplantation >3 months; 3) Combined with HBV/HVC/HIV infection in the donor or recipient; 4) Malignancy history in the donor and recipient; 5) organ transplant history in the recipient.