HLA-C and arthritic joint disease: In rats, the strong genetic association of MHC genes on chromosome 20 with susceptibility to different experimental arthritis models, including CIA, Mbt-AIA, PIA and OIA, was shown in different linkage analyses (Box 1) (Kawahito et al., 1998; Remmers et al., 1996; Vingsbo-Lundberg et al., 1998) and in MHC congenic strains (Griffiths and DeWitt, 1981, 1984; Lorentzen and Klareskog, 1996; Olofsson et al., 2003b; Remmers et al., 2002).