The present study demonstrated that 1,25(OH)2D3 reduced the production of RANKL and the secretion of TNF-α, IL-17, and IL-6 in PBMCs of RA patients, which indicated that 1,25(OH)2D3 might be able to decrease damage of cartilage and bone in RA patients by regulating the expression of RANKL signaling pathway and pathway-associated cytokines. The gene discussed is TNF; the disease is rheumatoid arthritis.