For the detection of DSBs, the immunofluorescence microscopy of γH2AX and 53BP1 foci was performed in PBMCs of healthy donors, CP-CML patients in DMR/MMR, CP-CML patients with loss of MMR, de novo CP-CML patients, and BP-CML patients. This evidence concerns the gene TP53BP1 and chronic myelogenous leukemia, BCR-ABL1 positive.