CSF2 and chronic myelogenous leukemia, BCR-ABL1 positive: However, while GM-CSF promotes cell proliferation in both AML blasts and K562 chronic myeloid leukemia (CML) cells in a tyrosine kinase-dependent manner, we observed that cell survival was autonomous, growth factor-independent, and resistant to tyrosine kinase inhibition (Figure 1A and 1B).