SLC17A4 and systemic lupus erythematosus: Novel Tier 1 regions of SLE association in EA and the proximal genes include 4p16 (DGKQ), 6p22 (SLC17A4 and LRRC16A), 6q23 (OLIG3-LOC100130476), 8p23 (FAM86B3P), 8q21 (PKIA-ZC2HC1A) and 17q25 (GRB2).