To investigate the anti-inflammatory and immunomodulatory effects of the LACK156–173 epitope in arthritis, we synthesized rLACK (the synthetic polypeptide of the LACK156–173 epitope) and pLACK (the recombinant LACK156–173 epitope expression plasmid), and evaluated their effect on the development of CAIA, an animal model of RA. The gene discussed is CAST; the disease is Arthritis.