Genomics of IGH::IGF2BP1 and C/EBPalt DS-ALL. Positions and rearrangement partners of (A) IGF2BP1 and (B) CEBPD rearrangements, as identified by paired WGS data. For IGH::IGF2BP1 and IGH::CEBPD rearrangements, the specific IGH gene segments that CEBPD rearranged to are shown, all of which are IGHJ gene segments. (C) Hierarchical clustering identified 8 cases with similar gene expression signature to CEBPD-r DS-ALL, indicated as C/EBPalt (other) with purple color in the top bar denoting sample subtypes. (D) Mapping of CEBPA and CEBPE alterations in 5 C/EBPalt cases. (E) Comparison of expression of CEBPA, CEBPE, and CEBPD genes among DS-ALL subtypes. The 5 cases with CEBPA- or CEBPE-related genomic alterations in panel D are marked by numbers. (F) Lollipop plot showing the location of FLT3 alterations in C/EBPalt DS-ALL. Most of the FLT3 alterations are in the juxtamembrane domain or the second tyrosine kinase domain. (G) FLT3 is highly expressed in the C/EBPalt subtype.