The Nalm6 32 (link) has been previously described. RPMI 1640 medium (Cellgro, USA) supplemented with 10% fetal bovine serum (Hyclone, USA) and DMEM (Cellgro) supplemented with 10% fetal calf serum and 1% L-glutamine (Cellgro) were used for culture of Nalm6 and HEK293 cell, respectively, incubated at 37°C in a humidified atmosphere of 5% CO2. Primary human B-ALL were cultured in RPMI 1640 medium (Cellgro) supplemented with 10% fetal bovine serum (Hyclone). CX4945 was obtained from Sigma (St. Louis, MO, USA). Cells were cultured with or without CX4945 and collected for total RNA isolation. Human IKZF1 retroviral construct and retroviral production were described previously 14 (link), 15 (link), 19 (link), 20 (link).