RUNX1 and precursor B-cell acute lymphoblastic leukemia: A unique feature of this B-ALL compared to subsequent B-ALL models was its origin in the kidney-marrow, which was confirmed by successful transplantation of kidney-marrow cells of Xef1a:TEL-AML1 leukemic fish into irradiated recipients, where all transplanted recipients developed B-ALL 6–9 weeks after transplant.