– Osteocrin is a secreted protein which is primarily expressed in bone and muscle. It is synthesized as a proprotein that undergoes proteolytic processing to generate a mature 50 amino acid C-terminal active peptide.Human Osteocrin proprotein shares 77% and 78% amino acid sequence identity with the rat and mouse protein, respectively. It appears to modulate osteoblastic differentiation. It could also function as an autocrine and paracrine factor linked to glucose metabolism in skeletal muscle.