The early successful application of molecular classification and targeted therapy, which was the beginning of a new paradigm for precision oncology, is the development of tyrosine kinase inhibitor (TKI) imatinib to treat patients with chronic myeloid leukemia (CML), caused by constitutively active BCR-ABL1 fusion tyrosine kinase [11]. Here, ABL1 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.