HLA-DRB1 and rheumatoid arthritis: In addition, the enrichment in the cohort of the rare HLA haplotype (B*14:02; C*08:02; DRB1*01:02; DQB1*05:01) and its previous association with other autoimmune diseases and hormone imbalance suggests that it may be involved in defining the patients’ phenotype (i.e., drug-resistant RA/PsA) [26].