It has also been reported that cytokine released from arthritis-affected joints, inparticular IL-1β, can stimulate the secretion of metalloproteinases (MMPs),especially MMP-2 and MMP-9, in endothelial and vascular smooth muscle cells, whichmay reduce the action of vasoconstrictor agonists (39,40). The gene discussed is MMP9; the disease is arthritic joint disease.