It has been discovered that HSP90AA1 expression was elevated in the peripheral blood mononuclear cells of a number of autoimmune diseases, including ankylosing spondylitis, systemic lupus erythematosus, and fibromyalgia syndrome [36,37,38,39,40], which was seemingly inconsistent with our results that HSP90AA1 was downregulated in IC/BPS. Here, HSP90AA1 is linked to ankylosing spondylitis.