Imatinib treatment of CML iCD34+ cell cultures was associated with a significant increase of slowly dividing CD34+ cells (generations 2–4) in bulk cultures (Supplementary Fig. S2a and b) and retention of CD34+ expression by rapidly dividing cells (generations 5–7; Supplementary Fig. S2c) as compared to non-treated cells. Here, CD34 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.