As the 3 GWAS significant loci for TPOAb levels also showed associations with TPOAb-positivity (TPO-rs11675434: OR, 1.21 [95% CI, 1.15–1.28)], P = 1.5×10−16; MAGI3-rs1230666: OR, 1.23 [95% CI, 1.14–1.33], P = 1.5×10−6; KALRN-rs2010099: OR, 1.24 [95% CI, 1.12–1.37], P = 7.4×10−5), we subsequently studied the (combined) effects of these 5 SNPs on clinical thyroid disease. The gene discussed is MAGI3; the disease is thyroiditis.