CD8A and acute lymphoblastic leukemia: For example, recent studies using the Mx1-Cre transgene to conditionally delete Dnmt3a in hematopoietic stem and progenitor cells (HSPCs) followed by transplantation into lethally irradiated recipients showed that a vast majority of mice develop myeloid disorders such as myeloid dysplastic syndrome and acute myeloid leukemia (69%) with rare occurrences of CD4+CD8+ double positive T-ALL (<12%) or B-ALL (<4%) [13].