The prevalence and severity of chronic kidney disease (CKD) has been increasing for decades. Because of its tremendous financial and health burden, both to persons and to health systems, mitigation of the progression of CKD is of critical importance. Two articles in this issue of the Journal report the primary results of separate randomized, controlled clinical trials that address the use of urate-lowering therapy for the prevention of kidney disease progression. Doria et al.1 present the results of the Preventing Early Renal Loss in Diabetes (PERL) trial, which investigated the use of a xanthine oxidase inhibitor, allopurinol, in patients with . . .