Macrophage Colony-Stimulating Factor (M-CSF) is a 19.02 kDa hematopoietic Growth Factors with 162 amino acid residues. The active form of the protein is homodimer, and secreted by osteoblasts. M-CSF controls the production, differentiation, and function of monocytes, macrophages, and bone marrow progenitor cells. M-CSF is able to activate CSF-1 signaling pathway via binding its receptor CSF-1R.