TNF and osteoporosis: Several studies have shown that estrogen deficiency and bone inflammatory pathologies, through increased ROS production, can cause apoptosis and alter osteocyte function with consequent up-regulation of factors, such as sclerostin, RANKL, TNFα, FGF23, and other signaling molecules involved in bone pathologies, such as osteoporosis, and in inflammatory diseases of other organs [14,39,57].