Among its components, Herba Epimedii (termed Yinyanghuo in Chinese) and the active ingredient icariin, may have a potential role in the prevention and treatment of osteoporosis by increasing the mRNA expression levels of osteoprotegerin (a TNF-related cytokine), bone morphogenetic protein (a promoter of osteogenesis) and collagen I (synthesized by active osteoblasts) in oophorectomized rats (16), as well as inducing estrogen biosynthesis (17). The gene discussed is TNFRSF11B; the disease is osteoporosis.