The inclusion of BCR::ABL1 tyrosine-kinase inhibitor (TKI) in the first-line treatment of chronic myeloid leukemia (CML) and positive B-cell precursor acute lymphoblastic leukemia (ALL) with Philadelphia (Ph) chromosome increased the life expectancy of these patients1,2. The gene discussed is BCR; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.