In addition, both VDR and PPAR-γ are key autophagy regulators [16, 17] and play central roles in the development and progression of RA, supporting the possible involvement of autophagy in RA. In vivo and in vitro experiments confirmed that the PPAR-γ agonist could downregulate inflammatory cytokines [18, 19]. This evidence concerns the gene PPARG and rheumatoid arthritis.