ENTPD1 and rheumatoid arthritis: For IFNγ-producing CD8+ T cells of RA patients, results mirrored those of CD4+ T cells, as the percentage was higher in cultures with IL-6, irrespective of CD39 expression (p = 0.006 in CD39+ subset and p = 0.003 in CD39− subset) and CD73 expression (p = 0.02 in CD73+ subset and p = 0.001 in CD73− subset).