Effector phase is similar between cystatin C-deficient and control mice. CAIA was induced with two monoclonal anti-CII antibodies by i.v injection into cystatin C-deficient (Cyst C -/-, n = 6), cystatin C heterozygous (Cyst C -/+, n = 9) and WT littermate controls (Cyst C +/+, n = 10). A, No significant difference was seen in incidence of arthritis. B, There was also no difference in arthritis severity when comparing affected mice (Cyst C -/- n = 4, Cyst C -/+ n = 8, Cyst C +/+ n = 9, mice were excluded if no clinical signs of arthritis was seen after 20 days post antibody injection). The error bars indicate SEM.