COL11A2 and rheumatoid arthritis: Furthermore, it has been suggested that the risk of RA is increased in patients with osteoarthritis, presumably due to increased inflammatory cytokines and citrullinated proteins in the joints of osteoarthritis patients,[20] and osteoarthritis, caused by the variants in the COL11A2 gene, may also have contributed to the development of seropositive, inflammatory arthritis in this patient.