Restored expression of CBY1 in CML patients at the time of complete or major molecular response during treatment with TK inhibitors (when the whole or major part of hematopoiesis is the normal, BCR-ABL1- one) supports CBY1 down-modulation as a trait of leukemic clone. The gene discussed is TKT; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.