HLA-DRB1 and systemic lupus erythematosus: Next, increase of HLA-G 14 bp ins was observed not only when compared with healthy controls, but also in the case-case analysis which compared SLE patients with the age of onset <20 and ≥ 20 years, while DRB1*13:02 did not show significant association in the case-case analysis (S4 Table).