IL17A and rheumatoid arthritis: Augmented levels of IL-17A have been reported in peripheral tissues and the central nervous system in some autoimmune and neurodegenerative disorders, such as psoriasis, rheumatoid arthritis and multiple sclerosis (Luchtman et al., 2014; Beringer et al., 2016; Blauvelt and Chiricozzi, 2018).