ATAC-seq using the Fast-ATAC10 method was performed on recently harvested primary ALL cells from 156 patients spanning ten B-ALL molecular subtypes (BCR::ABL1, DUX4-rearranged, ETV6::RUNX1, high hyperdiploid, low hypodiploid, KMT2A-rearranged, Ph-like, PAX5-altered, TCF3::PBX1, and ZNF384-rearranged) and B-other samples (Table S1) from diverse medical centers, research groups, and clinical trials networks across the United States (see STAR Methods). Here, TCF3 is linked to acute lymphoblastic leukemia.