IL6 and Intervertebral disk degeneration: Estrogen deficiency, as was similarly induced in the OVX model in the present study, is not only the main cause of bone loss, but is also accompanied by a progressive proinflammatory status, evidenced by increased systemic interleukin (IL)-1, IL-6, and tumor necrosis factor-α [26], which are potentially important in the pathogenesis of intervertebral disc degeneration [27, 28].