The most primitive (lineage negative, CD34+ CD38−/+) leukemia stem and progenitor cells (LSC/LPC) from CP CML patients were found to have higher (2- to 4-fold) ROS levels compared to normal HSC, which were not corrected by inhibition of BCR-ABL1 kinase activity with TKI [11]. Here, CD38 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.