(A–H) Leukemia development in recipient mice. Images are from a representative recipient of a primary transplant. Leukocytosis was observed in the blood smears (A). Blasts were present in the peripheral blood (B), BM smear (C), lymph node (D), spleen (E and F), and liver (G and H). Original magnification, ×40 (A, E, and G), ×200 (D, F, and H), ×600 (B and C). (I) SALL4 expression was determined by IHC staining in SALL4B leukemic BM cells. Original magnification, ×600. (J) Validation of HOXA9 upregulation in SALL4B leukemic GMP population. qRT-PCR analysis of gene expression in SALL4B leukemic GMPs compared with control normal GMPs. Measurements were from 3 individual secondary transplanted recipients (n = 3), each performed in triplicate. *P < 0.05. (K) Flow analysis of donor cell subtype after secondary transplantation.