TNFRSF11B and osteoporosis: Icariin (Figure 1), the main active flavonoid glucoside isolated from Epimedium plant, is found to have a therapeutic effect on osteoporosis in ovariectomy rat models and postmenopausal women and has been shown to suppress the loss of bone mass and strength in distal femur in tibia following OVX through increasing the mRNA expression ratio of OPG/RANKL [21, 22].