In particular, a recent report indicated that targeting SOS1 overcomes imatinib resistance in CML [53,54], raising interest in clinical testing against CMLs for various recently developed small-molecular antiSOS1 drugs [28,55,56,57,58,59], which could prove particularly useful as an alternative when resistances frequently arise after sustained treatment with the classical imatinib or other second-generation TKI inhibitors [8,60]. This evidence concerns the gene SOS1 and chronic myelogenous leukemia, BCR-ABL1 positive.