ABCG2 and hyperuricemia: Three transporter genes SLC2A9, SLC22A12, and ABCG2 have the largest contribution to risk for hyperuricemia and gout, but where the protein products for these genes, SLC2A9/Glut9, URAT1, and ABCG2, respectively, localize, where they are important for urate excretion, and how they contribute to urate homeostasis remains largely undefined.