To verify the in vivo function produced by IgG mut-B2 through blocking CTGF, we used a CIA mouse model, one of the most classic RA models, to study the efficacy of IgG mut-B2 in the progress of RA, as illustrated in Fig. 3A. Clinical scores and paw swelling were significantly reduced after injecting IgG mut-B2, compared with CIA mice injected with control IgG (Fig. 3B, Additional file 2: Table S3). Here, CCN2 is linked to rheumatoid arthritis.