Using the HLA-DRB1*01:01, *04:01, and *04:04 alleles that are all genetically associated with RA and commonly found in our cohort of RA patients, we initiated this study by demonstrating that the autoantibody levels toward citrullinated α-enolase are significantly increased in HLA-DRB1*04:01-positive RA patients compared to *01 and *04:04 RA patients. The gene discussed is HLA-DRB1; the disease is rheumatoid arthritis.