Further genetic analyses focusing on SNPs in genes encoding the targets of urate-lowering drugs (eg, SNPs in XDH, which encoded xanthine oxidoreductase, the target of allopurinol, should these be shown to be associated with urate concentration), using a range of clinical outcomes, including but extending beyond coronary heart disease, would be necessary to address this distinct question, as has been done for other potential therapeutic targets.27, 28. The gene discussed is XDH; the disease is coronary artery disorder.