ABL1 and acute lymphoblastic leukemia: Intriguingly, alternative breakpoint usage generating multiple KGFs can also be found within the same cell line, as in CUTO-2 and SNU-16, where the same portion of the partner gene (SDC4 or APIP, respectively) is fused with 2 different breakpoints of the same kinase (ROS1 or FGFR2, respectively), or in ALL-VG, where two alternative breakpoints in the ETV6 partner gene generate 2 different KGFs with the same ABL1 kinase portion.