BCR and acute lymphoblastic leukemia: Our results showed that complex BCR-ABL1 signal patterns were observed in 52.9% (n = 9) of the CML-BP patients, followed by 30.8% (n = 16) of the BCR-ABL1 positive ALL patients and only 2.1% (n = 5) of the CML-CP patients (p < 0.001) (Fig. 2a).