IL17A and rheumatoid arthritis: Our data revealed that 72 hours after incubation of PBMCs with 1,25(OH)2D3 in RA patients, the levels of RANKL, TNF-α, IL-17 and IL-6 significantly decreased in 1,25(OH)2D3  treated groups compared with anti-CD3/CD28 group (P < 0.05; Table 3; Figures 1, 2, 3, and 4).