We conducted a targeted assessment for the enrichment of known gene sets derived from multiple immature or lineage-ambiguous leukemias, including: early T-cell progenitor (ETP) ALL18, KMT2A-rearranged B-cell ALL19, early pro-B BCR-ABL + B-ALL20, hematopoietic stem cell (HSC)-like AML21, the acute myeloid leukemia stem cell (LSC)-4722, and B-ALL with subsequent monocytic lineage switch23. The gene discussed is BCR; the disease is leukemia.