Progression of chronic myeloid leukemia. Chronic myeloid leukemia (CML) is characterized by an excessive proliferation of non-functional leukocytes (dotted lines) or blasts in the bone marrow and then in the blood. The chronic phase remains generally asymptomatic, during which 5% blasts are found in the bloodstream. After 5 to 6 years without treatment, the pathology progresses towards the accelerated phase (5% to 20% blasts) and symptoms including fatigue and loss of appetite and weight begin to appear. Without treatment, the accelerated phase progresses in 6 to 9 months to the blast phase (more than 20% blasts), causing rapid deterioration of the general condition of the patient and death after only a few months without management. Symptoms and resistance to therapy increase during the course of chronic myeloid leukemia, while the probability of survival decreases.