ACS and APS also modified the inflammatory response by increasing the gene expression of the anti-inflammatory cytokine IL-10 and decreasing the concentration of PGE2. Additionally, APS downregulated the expression of MMP-1 in synovial membrane, which is one of the main collagenases produced primarily by the synovial cells (24). The gene discussed is MMP1; the disease is autoimmune polyendocrinopathy.