In addition, RF – pJIA has been also associated with HLA-DPB1*03, while RF + pJIA, which can be regarded as the paediatric counterpart of adult RA, has been associated with HLA-DRB1*01, HLA-DRB1*04, HLA-DQA1*03, and HLA-DQB1*03 [19,76,88]. This evidence concerns the gene HLA-DRB1 and rheumatoid arthritis.