TGF-β (A) and IL-10 (B) concentrations in supernatants of Treg/peripheral blood mononuclear cell (PBMC) cultures. Production of TGF-β and IL-10 caused by anti-CD3 + IL-2 stimulation was significantly higher than under IL-7 or IL-15 influence in both groups. In addition, the production of these cytokines was significantly higher in RA patients than in HDs under anti-CD3 + IL-2. Median and IQR. Unrelated groups were compared using the Mann–Whitney test. A comparison of related groups was performed using the Friedman test (ANOVA), and post hoc analysis was performed using the Dunn test. RA, rheumatoid arthritis (n = 7); HDs, healthy donors (n = 5); W/O, without stimulation.