TNFSF11 and osteoporosis: Recently, it has been shown that epigenetics has an important role in regulating the differentiation of bone marrow mesenchymal stem cells (MSCs) into OBs and OCs by regulating the expression of genes in the estrogen endocrine pathway, the Wnt/β-catenin signaling pathway, the OPG/RANKL/RANK system, the vitamin D endocrine pathway and other metabolic-related pathways, and thus regulating the differentiation and activity of OBs and OCs, thus participating in the development of osteoporosis (Park-Min, 2017).