(1) CCR5+CXCR3+ IL-17-producing Vδ2 T in RA;(2) TEM Vγ9+Vδ2+ IL-17-producing T cells with HLA-DR and CD86 expression in SF of RA;(3) TEMγδ17 T cells in peripheral and synovium of PsA;(4) IL-23R+RORγt+ γδ17 T cells in active AS and other SpA. Here, IL17A is linked to rheumatoid arthritis.