We found that: 1/HLA-DRB1*04:01 was associated with anti-α501-515cit antibodies, 2/Rheumatoid nodules were associated with HLA-DRB1*04:01, 3/”High level” anti-α501–515cit antibodies were associated with rheumatoid nodules and with IgM rheumatoid factor. The gene discussed is HLA-DRB1; the disease is rheumatoid arthritis.