In this view, we investigated the possible impact of a short course of cytoreduction with HU both on WBC counts and on quantitative BCR::ABL1 level changes, if any, either at diagnosis and on day 7 and day 14 of treatment in a cohort of patients with newly diagnosed BCR::ABL1-positive CP-CML treated with or without cytoreduction with HU before frontline treatment with TKIs. The gene discussed is BCR; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.