A receptor called OSCAR on bone cells binds collagen to help form bone-resorbing cells (osteoclasts), which is crucial for bone remodeling.

“Human osteoclast-associated receptor (OSCAR) is another collagen receptor that belongs to the immunoglobulin (Ig) superfamily. This receptor is expressed in a wide range of myeloid cells and is specifically involved in osteoclast growth induction for bone resorption. Collagen binding to OSCAR leads to conscription of immunoreceptor tyrosine-based activation motifs (ITAM) containing FcRγ chains. This process further activates the downstream effect of calcium signaling, which is essentially important for the activation of an osteoclastogenic transcription factor such as the nuclear factor of activated T-cells (NFAT) c1.”