The approach was first used in the 1980s and 90s to engineer leukemia and lymphoma models driven by the IGH-MYC and BCR-ABL translocations, and quickly became the most widely used technique to model chromosomal rearrangements (Shtivelman et al., 1985; Heisterkamp et al., 1990, 1991; Adams et al., 1985). Here, ABL1 is linked to leukemia.