To do so, Mcl-1f/fArf-deficient pre-B cells expressing the p185 isoform of BCR-ABL (hereafter referred to as p185+ B-ALL) were stably transduced with cDNAs encoding human BCL-2, BCL-XL, BCL-W, MCL-1, or BFL-1 (also known as BCL2A1). Here, ABL1 is linked to acute lymphoblastic leukemia.