Use of a non-human mammalian disease model, wherein the non-human mammal has been implanted with human synovial tissue or other human inflamed tissue containing anti-CCP (cyclic citrullinated peptide) antibody producing cells for (i) analyzing cellular processes in a disease associated with anti-CCP antibodies in such human synovial tissue or other human inflamed tissue, (ii) studying the role of anti-CCP antibodies in the induction and progression of a disease associated with anti-CCP antibodies, (iii) testing the efficacy of a therapeutic agent for the prevention or treatment of a disease associated with anti-CCP antibodies, and (iv) identifying a therapeutic agent useful for the prevention or treatment of a disease associated with anti-CCP antibodies. In one embodiment the non-human mammalian disease model is a mouse, such as a SCID mouse, and the disease associated with anti-CCP antibodies is arthritis, such as RA (rheumatoid arthritis).