While inhibition of both ABL paralogs might contribute to the observed side effects of imatinib treatment (Buchdunger et al., 1996), imatinib is used to target c-kit-mutated gastrointestinal stroma tumors (GIST) or PDGFRβ-mutated chronic myelomonocytic leukemia (CMML, Table 1) (Poveda et al., 2017; Valent et al., 2019). Here, ABL1 is linked to gastrointestinal stromal tumor.