ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: Therefore, routine detection of the BCR/ABL fusion genes in peripheral blood and bone marrow smears is recommended for patients with unexplained solitary thrombocythemia to confirm the possibility of atypical CML, which is associated with poor prognosis and a median overall survival of 24 months.[19] Valencia et al[20] reported that imatinib effectively improved the prognosis of patients with variant Philadelphia chromosome similar to that of patients with the classic Philadelphia translocation.