HLA-DRB1 and systemic lupus erythematosus: SLE patients with HLA-DRB1*04 allele were significantly correlated to the increased levels of cytokines such as IL-18, IL-21, IL-17F, IFN-γ, and GM-CSF and VEGF compared to SLE patients without HLA-DRB1*04 allele and healthy controls.