Minimal residual disease (MRD) is the major cause of leukemia relapse. It has been reported that the treatment intensity in human leukemia can be assessed by the expression status of MRD gene. However, more than 50% of acute leukemia, especially in AMLs, lack known genetic lesions or clonegenic markers suitable for MRD monitoring. WT1 gene is located on chromosome 11p13 coding for a zinc-finger transcription factor, has been identified in most AML patients. It has been reported that detection of WT1 levels can effectively monitor the MRD expression status in AML.16,17 Therefore, WT1 expression can be used to monitor the MRD and evaluation the remission quality in AML patients. By detecting WT1 levels we can evaluate the efficacy of different induction therapies.