Inclusion Criteria:

- The patient must have given his/her informed and signed consent

- The patient must be insured or beneficiary of a health insurance plan

Inclusion Criteria for all CML patients

- Patients diagnosed with CML

- Treatment with Imatinib in first-line monotherapy and this for at least 18 months

- RNA and / or cDNA used for diagnosis correctly stored in the biobank

Inclusion Criteria for CML patients already having undergone 28-24 months of followup

- RNA and / or cDNA used for diagnosis/follow-up correctly stored in the biobank

- Cytogenetic results are available

- Absence of ITK mutation for the primary resistance subgroup

- Validated compliance

Inclusion Criteria for the control population

- Absence of hematologic malignancy

Exclusion Criteria:

- The patient is participating in another study

- The patient is in an exclusion period determined by a previous study

- The patient is under judicial protection, under tutorship or curatorship

- The patient refuses to sign the consent

- It is impossible to correctly inform the patient

- The patient is pregnant, parturient, or breastfeeding

- The patient has a contraindication for a treatment used in this study

Exclusion Criteria for CML patients already having undergone 28-24 months of followup

- Known or suspected cause for resistance (dose reduced due to intolerance, digestive
disease responsible for malabsorption ...)

Exclusion Criteria for the control population

- History or suspicion of hemopathy