Next, we assessed whether the response to AZD1775 was sustained over time, by measuring recovery of proliferation post-treatment in leukemia cell lines, comparing the different chromosomal translocations, including ETV6-PDGFRB (Nalm-6), TCF3-PBX1 (697, RCH-ACV and Kasumi-2), ETV6-RUNX1 (REH), and KMT2Ar-ALLs (RS4;11, SEM, ALL-PO and KOPN8). This evidence concerns the gene TCF3 and acute lymphoblastic leukemia.