IL17A and rheumatoid arthritis: The IL-17 family consists of a group of proinflammatory cytokines with an active role in host defense, yet implicated in the pathogenesis of a wide range of immune-mediated diseases, including psoriasis, psoriatic arthritis, rheumatoid arthritis, ankylosing spondylitis, and others such as hidradenitis suppurativa [6–9].