For this purpose, we recently generated an ad hoc mouse colony by cross-mating a transgenic p210BCR/ABL-driven CML mouse model [33,34] with our SOS1/2-KO system, allowing us to generate WT, SOS1-KO, SOS2-KO, and SOS1/2-DKO mice [26,35]. This evidence concerns the gene SOS2 and chronic myelogenous leukemia, BCR-ABL1 positive.