These arthritis models include cartilage-restricted antigen-induced arthritis, which use type II collagen (CII), type XI collagen (CXI) or cartilage oligomeric matrix protein (COMP) as the antigen; and mycobacterial adjuvant-induced arthritis (Mbt-AIA), which induces disease by injection of heat-killed mycobacteria emulsified in IFA. The gene discussed is COMP; the disease is Arthritis.