HLA-DRB1 and rheumatoid arthritis: The prevalence and genetic susceptibility of RA can vary depending on ethnicity and racial stratification of SE-encoded HLA-DRB1 alleles, with the HLA-DRB1∗04:01 allele possessing the highest risk of RA development (odds ratio (OR) of 4.44), alongside with HLA-DRB1∗04:04 (odds ratio of 4.22), HLA-DRB1∗01:01 (OR of 2.17), and HLA-DRB1∗10:01 (OR of 4.22) are the predominant SE-encoding alleles in Europeans (15).