Although BMP4 stimulation did not alter the capacity to divide, untreated CML cells underwent a 20.5% ± 12.6% (n = 3) expansion in CD34+ numbers following BMP4 stimulation, with no change observed in normal CD34+ numbers (Figure S4E–iii), confirming CML cells are more responsive to BMPs16. This evidence concerns the gene CD34 and chronic myelogenous leukemia, BCR-ABL1 positive.