The function of OCSTAMP (osteoclast stimulatory transmembrane protein, ENSG00000149635) is as follows. Probable cell surface receptor that plays a role in cellular fusion and cell differentiation. Cooperates with DCSTAMP in modulating cell-cell fusion in both osteoclasts and foreign body giant cells (FBGCs). Involved in osteoclast bone resorption. Promotes osteoclast differentiation and may play a role in the multinucleated osteoclast maturation (By similarity). .