Objective To study the changes of minimal residual disease(MRD) in children with B cell acute lymphoblastic leukemia(B-ALL) of different genetic abnormalities. Methods Between February 2004 and April 2013, 271 newly diagnosed B-ALL pediatric patients who had finished the induction chemotherapy were enrolled in the study. The characteristics of changes in MRD in patients with different genetic abnormalities on the 15th day and at the end of the induction therapy were analyzed. Results On the 15th day of the ...