Based on the observation that both IL-20 and IL-20R1 are highly expressed in the CIA rats’ synovial tissue, we intra-muscularly electroporated soluble IL-20R1 (sIL-20R1) plasmid DNA to block IL-20’s function through inhibiting IL-20R1 signaling and found that the arthritis severity of the CIA rats was significantly reduced. Here, IL20 is linked to arthritic joint disease.