Th17 cells from axSpA, PsA and RA patients and HCs were characterized as CD4+CD45RO+CD161+CCR6+CCR4+CXCR3− cells and analyzed for IL-1R1 (Figures 2C, D; for the gating strategy, see Supplementary Figure S2B). Here, CCR4 is linked to rheumatoid arthritis.