Philadelphia chromosome, t (9; 22): BCR-ABL1 was reported in chronic myeloid leukemia (CML), and is used as diagnostics for CML and also some uncertain cases of acute leukemia, and is associated with the worst prognosis in children and adults (Kang et al., 2016; Sampaio et al., 2021). The gene discussed is ABL1; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.