A total volume of 10 mL of PB in ethylenediaminetetraacetic acid was obtained from 66 healthy volunteers and from a cohort of 23 IMA naïve de novo CML patients (month 0 5 M0 samples). CML patients were investigated monthly for a period of 6 months from the start of IMA treatment (M1-M6 samples). All volunteers and patients signed an informed consent form and the study was approved by the institutional review board.