Because the serum levels of anti-citBiP antibodies were higher than those of anti-BiP antibodies in 72% of RA patients, and the location of the major epitopes of anti-citBiP and anti-BiP antibodies were different in RA patients, the development of anti-citBiP antibodies can be a distinct process in the pathogenesis of RA. This evidence concerns the gene HSPA5 and rheumatoid arthritis.