Similar to NGF, BDNF regulates new bone formation through induction of osteoblast proliferation and differentiation.[123] Brain‐derived neurotrophic factor also enhances RANKL secretion by human BMSCs, which contributes to osteoclastogenesis.[126] In vivo experiment showed that BDNF promoted osteosclerosis after cortical osteotomy.[127] TrkB, which binds exogenous BDNF, is expressed by chondrocytes, osteoblasts, osteoclasts, and cementoblasts. This evidence concerns the gene BDNF and osteosclerosis.