TNFRSF11B and osteoporosis: Their dysregulation impedes bone metabolism, leading to osteoporosis via regulating the transforming growth factor-β (TGF-β)/bone morphogenetic protein (BMP) pathway, Dickkopf-1 (DKK1), Runt-related transcription factor 2 (RUNX2), the receptor activator of nuclear factor kappa B (RANK)/RANK ligand (RANKL)/osteoprotegerin (OPG) pathway, and WNT signaling [39,41,42,43].