PTPRC and leukemia: We found that OF-YM BMT mice developed predominantly B/myeloid mixed phenotype acute leukemia (B/M MPAL), a leukemia of hematopoietic stem/progenitor cell (HSPC) origin [37], which was defined morphologically and phenotypically by ≥20% blasts in peripheral blood or bone marrow that were positive biphenotypically for both B (B220+) and myeloid lineage (Mac1/Gr1+) markers (Fig. 2f, g and Supplementary Fig. 3d), as described previously [38].