Moreover, while CD19+ but not CD19- progenitors from either ETV-RUNX1 or p190 BCR-ABL can give rise to leukemic reconstitution, the CD19- (uncommitted) cells of p210 BCR-ABL ALL, in spite of harboring the chromosomal translocation, gave rise, when transplanted to NOD-SCID mice, to normal multilineage human hematopoiesis. This evidence concerns the gene ABL1 and acute lymphoblastic leukemia.