HLA-DRB1 and systemic lupus erythematosus: Our data reveal a second independent signal at the MHC in SLE arising from the T allele of SNP rs419788 in intron 6 of the class III gene, SKIV2L. Further evidence supporting the independence of the rs419788-T and HLA-DRB1*0301 alleles is provided by the moderate LD between these two variants (r2 = 0.24) coupled with our data demonstrating that only 47% of rs419788-T allele-bearing haplotypes contain HLA-DRB1*0301.