CSF2 and chronic myelogenous leukemia, BCR-ABL1 positive: In marked contrast, the CML G0 cells shown in Figure 2(c), when stimulated in the absence of EPO by all the single cytokine and combinations shown (except G-CSF alone and G-CSF+GM-CSF), produced a mixture of CFU-GM and CFU-E/BFU-E with about a third to one half of the colonies being erythroid or mixed and often very large.