The association of HLA-DRB1*01 with therapeutic resistance in JIA has further support from a study by Ali et al. [34] involving a Pakistani population, which found that patients with HLA-DRB1*03 were significantly more likely to have an inadequate response to MTX, a first-line immunomodulatory therapy. This evidence concerns the gene HLA-DRB1 and juvenile idiopathic arthritis.