At 1 hour of PTL or DMAPT treatment CML cells from cell lines and CD34+lin− CML‐CP showed an increase in DCFDA MFI, compared to untreated cells, indicating an increase in ROS levels, importantly primitive cells from NBM did not show an increase in ROS levels. The gene discussed is CD34; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.