ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: Furthermore, it is also worth noting that the SOS1-dependent delay of CML observed here is not an off-target effect of TAM treatment since TAM treatment did not by itself cause any changes in the kinetics of the survival of the control p210BCR/ABL transgenic mice that were also WT for both SOS1 and SOS2.