Notably, unusually high frequency extended haplotypes comprising variants associated with systemic lupus erythematosus (SLE), multiple sclerosis (MS) and type I diabetes were identified for the HLA-DR2, HLA-DRB1 and HLA-C loci in samples of European descent [27], illustrating again how the identification of immune loci with signatures of recent positive selection may be a good strategy to identify functionally relevant variation and suggest candidates to test for association to immune related diseases [4,28]. This evidence concerns the gene HLA-C and systemic lupus erythematosus.