ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: Biochemical studies of target spectrum indicates that imatinib is the most specific CML TKI and it does not inhibit VEGFR signaling; on the other hand, ponatinib has the broadest substrate spectrum as it inhibits FGFRs, VEGFRs, PDGFRs, KIT, SRC, TIE2, etc. in addition to ABL ((Moslehi and Deininger, 2015; Zeng and Schmaier, 2020; Lee et al., 2021).