Imatinib, a tyrosine kinase inhibitor (TKI) that targets ABL, BCR-ABL, PDGFRA, and c-KIT, is widely used in treating chronic myelogenous leukemia (CML) and gastrointestinal stromal tumors (GIST). Here, ABL1 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.