KITLG and chronic myelogenous leukemia, BCR-ABL1 positive: To analyze if S63845 treatment might induce apoptosis of CML stem/progenitor cells, we tested (in the presence of SCF, FL, and TPO) the impact of S63845, imatinib, and their combination on the ratio of activated caspase-3/7 expressing CD34+ stem/progenitor cells isolated from two CML patients at diagnosis, using fluorescence live cell microscopy (Fig. 7C, D; Supplementary Fig. 4).