In the field of hematology, studies of liquid biopsies, in terms of CTC, have been carried out over the last few years, such as in CML (with a treatment adjustment in terms of BCR/ABL1 peripheral blood leukocyte RNA in CML patients, as well as adjustments in terms of the NPM1-mutated ratio in peripheral blood leukocyte RNA in AML). The gene discussed is BCR; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.