We observed that 38 of 92 patients with BD (41%), 16 of 92 with RA (17%), 10 of 90 with SS (11%), and 1 of 90 HC (1%) were anti-ETFB positive, indicating that the anti-ETFB antibody had a significantly higher prevalence in BD than RA (P<0.0001), SS (P<0.0001) or HC (P<0.0001), which further confirmed that ETFB is an autoantigen in BD (Fig 5). This evidence concerns the gene ETFB and rheumatoid arthritis.