GM-CSF is a monomeric cytokine with two glycosylation sites that stimulates the growth and differentiation of hematopoietic precursor cells from various lineages, including granulocytes, macrophages, eosinophils and erythrocytes. CSF2 is secreted together with other factors by T cells and macrophages following cell activation by antigens or mitogens. The signalling ‘GM-CSF:receptor’ complex is a dodecamer of two hexamers of two alpha, two beta, and two ligand subunits. While non-glycosylated and glycosylated GM-CSF show similar activities in vitro, fully glycosylated GM-CSF is biologically more active in vivo. Recombinant Mouse CSF2 is a non-glycosylated, monomeric protein.