Granulocyte Macrophage Colony Stimulating Factor, GM-CSF, is hematopoietic factor produced by endothelial cells, monocytes, fibroblasts and T cells in response to a number of inflammatory mediators. GM-CSF is able to stimulate the production of neutrophilic granulocytes, macrophages, and mixed granulocyte-macrophage colonies from bone marrow cells. GM-CSF can also stimulate some functional activities in mature granulocytes and macrophages. and GMCSF show no cross-reactivity. Recombinant GM-CSF is a non-glycosylated Protein, containing 125 amino acids, with a molecular weight of 14.3 kDa.