HLA-DRB1 and rheumatoid arthritis: The “A” allele at the position 9,304 was observed in the RA-susceptible alleles (DRB1*04:01:01:03, DRB1*04:05:01:01, DRB1*04:05:01:02, DRB1*04:05:01:03, and DRB1*04:10:03).