Effects of USP1 siRNA in B-ALL cells. (A) After transfection with USP1-siRNA, real-time PCR and was used to quantify the mRNA levels of USP1. **, P < 0.01; #, P > 0.05 versus the other two groups. (B) Western blot was used to detect the protein level of USP1. Lane 1, Control group; lane 2, NC-siRNA group; lane 3, USP1-siRNA group. (C) Depletion of USP1 inhibited the cell growth of CCRF-SB and Sup-B15 cells. Data were presented as mean ± SD; **, P < 0.01 versus other two group; #, P > 0.05. (D) The effect of USP1 siRNA on apoptosis of CCRF-SB and Sup-B15 cells was determined by flow cytometry. Data were shown as mean ± SD; **, P < 0.01 in comparison to the control group; #, P > 0.05.