Effect of B55α suppression on drug resistance in OCI-AML3 cells. OCI-AML3 cells containing control (NS) lentiviral plasmid or cells containing B55α shRNA lentiviral plasmid were treated with vehicle (0.1% DMSO), 1 µM AraC, 3 µM AraC, or 5 µM FTY-720 for 48 h. Total viable cells were determined by analytical flow cytometry as described in the “Materials and methods”. The Student t-test was performed to determine statistical significance (*, p = 0.014; **, p = 0.006, ***, p b 0.001).