TNF and osteoarthritis: It is suggested that the BM microenvironment may be a key factor in the pathogenesis of this disease.2 In addition, an increase in the pro‐inflammatory factors tumor necrosis factor (TNF)‐α, interleukin (IL)‐6, and IL‐15 in the BM of the elderly can stimulate osteoclast bone resorption, which may be related to the susceptibility of the elderly to osteoporosis and osteoarthritis.6