HLA-DRB1 and systemic lupus erythematosus: Previous studies which indicated that the class II alleles HLA-DR2 (DRB1*1501) and HLA-DR3 (DRB1*0301) confer a two- to three-fold greater risk for SLE development is in agreement with our findings [11,31,32,33,34,35,36,37,46,47,50].