Human CD34 cells expressing TCF3::ZNF384 (TCZ) drive B/myeloid leukemia in vivo. A, Survival curves in primary recipients transplanted with indicated cells. B, Immunophenotyping from a representative mouse showing tumors express CD34, CD38, CD33, and CD19. C, Hematoxylin and eosin (H&E) staining (left), CD33 staining (middle), MPO staining (right) of sternal section and cytospin of bone marrow cells. Scale bars represent 50 µm for all except for bone marrow cytospin (scale bar, 20 µm). D, Single-sample GSEA displaying relative enrichment score (Z-score) for B-ALL subtype-specific gene lists. Experimental tumors are enriched for ZNF384r gene set. Patients 1–12 (non-ZNF384r) were included for heterogeneity, which is required for analysis. Adjacent samples labeled R1, R2, or R4 are relapsed samples from the same patient. TCZ, TCF3::ZNF384.