Next, we investigated the antileukemic effects of idasanutlin in a cohort of primary (n = 11) and primary-derived (PDX, n = 31) B- (n = 30) and T-ALL (n = 12) samples derived from pediatric and adult ALL patients representing various subtypes including KMT2A-rearranged, Ph+, TCF3::HLF, and low hypodiploidy ALL (Supplementary Table S1). Here, TCF3 is linked to acute lymphoblastic leukemia.