HLA-B and rheumatoid arthritis: [22] Previous research has indicated that a single nucleotide polymorphism (SNP) in the HLA-B locus, located at amino acid position 9 within the peptide binding groove, is associated with RA.[23] In this study, we report for the first time that alleles HLA-B*40:01:01G, *40:02:01G, *15:01:01G, and *54:01:01G are susceptible genes for RA in the Yunnan Han population.