TNFRSF11A and pulmonary emphysema: There may be congenerous molecular mechanisms involved in the destruction of both lung parenchyma and bone structure, and inflammatory cytokines, such as IL-1β, IL-6 and TNF-α, as well as the osteoporosis related protein triad OPG/RANK/RANKL, may have some synergetic effects on both emphysema and bone loss.