Description: CD115 or Colony-Stimulating Factor-1 Receptor (CSF-1R) is expressed on cells committed to the monocyte lineage and osteoclasts. CSF-1R is a disulfide-linked homodimer, which upon binding of its ligand, CSF-1, undergoes tyrosine autophosphorylation and subsequently, phosphorylates other membrane-proximal downstream targets which results in cytoskeletal remodeling, gene transcription and protein translation. CSF-1R activation promotes the survival, proliferation and differentiation of mononuclear phagocytes and the spreading and motility of macrophages. In osteoclasts, CSF-1R synergizes with RANKL to regulate the differentiation of mononuclear phagocytes to osteoclasts.