The IL-17/IL-17R axis has a role even in chronic pain in RA, as emerged from experimental data in a mouse model of neuropathic pain elicited by partial ligation of the sciatic nerve, in which the IL-17 knock-out mice demonstrated significantly lower pain hypersensitivity, decreased infiltration of T cells and macrophages into the sciatic nerve, and decreased activation of microglia and astrocytes in the L3–L5 dorsal and ventral horns of the spinal cord. This evidence concerns the gene IL17RA and rheumatoid arthritis.