The TH17-derived IL-17A cytokine is a potent inflammatory cytokine that has been implicated in a growing list of autoimmune diseases, for example, multiple sclerosis, Crohn's disease, rheumatoid arthritis, psoriasis, systemic lupus erythematosus, and SS, as well as autoimmunity in animal models [3]. Here, IL17A is linked to rheumatoid arthritis.