IL6 and neoplasm: Gabrilovich et al. demonstrated that growth factors produced by tumor cells, in particular vascular endothelial growth factor (VEGF), IL-6, IL-10, macrophage colony stimulating factor (M-CSF), and granulocyte–macrophage colony stimulating factor (GM-CSF), induced severe developmental defects in DCs as well as general dysfunction of myelopoiesis (144–147), and later studies showed that these effects can be traced to STAT3 activation in myeloid progenitors.