MCAM and rheumatoid arthritis: IL‐22 in synovial fluid also showed smaller enrichments within CD146+CD4 T cells (1·7‐ and 2·6‐fold, respectively, in SpA and RA, Fig. 9b) than in peripheral blood (4·8‐fold for both); for IFN‐γ, the trend was even reversed (0·8‐ and 0·85‐fold; Fig. 9c).