NGF and osteoarthritis: The two receptors of NGF, TrkA and p75NTR, are expressed by joint chondrocytes.[273, 274] Intra‐peritoneal injection of anti‐NGF antibody resulted in suppressed up‐regulation of CGRP in the dorsal root ganglion neurons.[275] Application of anti‐NGF antibodies reduced the number of tartrate‐resistant acid phosphatase‐positive osteoclasts in the subchondral bone in a murine model of osteoarthritis.[276]