IL17A and rheumatoid arthritis: For instance, it can regulate NF-κB and provides neuroprotection by suppressing pro-inflammatory cytokines TNF-α and IL-1β in AD brain, downregulate IL-6 and IL-17 expression in rheumatoid arthritis mice model, or suppress microgliosis and inflammatory cytokine production in the optic nerve of experimental autoimmune encephalomyelitis model (48, 96–98).