This view is compatible with a previous study showing that peptidoglycan-induced uveitis, i.e., non-infectious uveitis, is exacerbated in NOD2-deficient but not NOD1-deficient mice (26) and, more importantly, in the present study showing that anti-collagen antibody-induced arthritis is enhanced in mice bearing a Blau mutation even when the Blau mutation is present on only one allele in heterozygous mice. The gene discussed is NOD1; the disease is arthritic joint disease.