Instead, Woodcroft et al. used lethally irradiated mice transplanted with lin− BM (bone marrow) cells or cultured fetal liver progenitors encoding E2a-Pbx1 that revealed a complete block in B-cell development and a partial block in myeloid differentiation whereas leukemia with a myeloid phenotype was seen after transplantiation of cultured fetal liver progenitors transduced with E2a-Pbx1. This evidence concerns the gene PBX1 and leukemia.