Also in chronic myeloid leukemia dd-PCR showed a higher sensitivity with respect to the conventional PCR (Zagaria et al., 2015); in the ISAV study, dd-PCR, able to detect one BCR-ABL1-positive cell out of 10-7, was validated for its predictive role in terms of relapses after imatinib discontinuation in patients with undetectable transcript by QT-PCR. The gene discussed is BCR; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.