['acute lymphoblastic leukemia']
['chemotherapy']

        Inclusion Criteria:

          -  acute lymphoblastic leukemia

          -  18-39 years old

          -  in first complete remission -Adequate hepatic function defined as: total bilirubin
             ≤2.0 times the institutional upper limit of normal (ULN); alanine aminotransferase
             (ALT) and aspartate aminotransferase(AST) ≤2.5 times the institutional ULN -

          -  Adequate renal function defined as creatinine ≤3 times the institutional ULN

          -  No uncontrollable infection

          -  Performance Status(PS)score 0-2(WHO)

          -  Subjects able to provide written informed consent

        Exclusion Criteria:

          -  having HLA-matched donor

          -  high-risk ALL: (1)Ph+ALL (2)Hypodiploidy (3)t(v;11q23) (4) complex karyotype（≥5
             chromosome abnormalities）（5）high white blood cell (WBC) count (B-ALL≥30×109/L;T-ALL
             ≥100×109/L).

          -  pregnancy

          -  Loss of ability to freely provide consent due to psychiatric or physical illness
      