Despite the protective role played by the IL-23/IL-17 axis against bacterial and fungal infections, extensive knowledge supports the contribution of its dysregulation in triggering chronic inflammation and autoimmunity, providing a solid substrate for the development of several autoimmune diseases like PsA, Psoriasis, Psoriatic Arthritis; AS, Ankylosing Spondylitis; IBD, Inflammatory Bowel Disease; RA, Rheumatoid Arthritis; SS, Sjogren Syndrome; MS, Multiple Sclerosis (3, 7–10) (Table 1). The gene discussed is IL17A; the disease is synovial sarcoma.