In osteoarthritis, abnormal remodeling of subchondral bone and formation of osteophytes are often accompanied by neurovascularization.17,18 Previous studies have suggested that netrin-1, secreted by osteoclasts during abnormal subchondral bone remodeling, may induce sensory nerve innervation and osteoarthritis-related pain through its DCC (deleted in colorectal cancer) receptor.9 During bone remodeling, the level of prostaglandin E2 (PGE2) also increases in the subchondral bone. Here, NTN1 is linked to osteoarthritis.