SLE carriers with the HLA-DRB1*04 allele experienced increased levels of cytokines (IFNγ, GM-CSF, IL-17F, IL-18, IL-21, and VEGF) and significantly decreased levels of IL-5 and free radicals when compared to carriers SLE without the HLA-DRB1*04 allele [43]. This evidence concerns the gene IL21 and systemic lupus erythematosus.