Brady and colleagues reported that transplantation of fetal liver-derived murine hematopoietic stem and progenitor cells (HSPC) retrovirally overexpressing a human ERG ORF into sublethally irradiated mice resulted in fully penetrant megakaryoblastic leukemia.54 Tsuzuki and Seto55 found that transplantation of adult bone marrow (BM) cells from 5-FU-stimulated donor mice retrovirally expressing a human ERG ORF into lethally irradiated mice induced a leukemia-like disease characterized by accumulation of CD71+/Ter119+ erythroblasts and expansion of CD4+/CD8+ double positive T cells. This evidence concerns the gene ERG and adult acute megakaryoblastic leukemia.