TNF and ankylosing spondylitis: The feasibility of TNF-α antagonism as a novel strategy to treat HA clearly deserves a thorough investigation, especially if considering that, over the last two decades, anti-TNF-α biologics became the most powerful tools for controlling patients suffering from a number of rheumatic diseases, such as RA, psoriatic arthritis, and ankylosing spondylitis, with sustained efficacy and acceptable safety profiles as demonstrated in long-term follow-up studies [16,33,34].