Epalrestat is a carboxylic acid derivative that inhibits aldose reductase, a rate-limiting enzyme of the polyol pathways.[1–3] In hyperglycemia, epalrestat, an uncompetitive aldose reductase inhibitor, significantly reduces intracellular sorbitol accumulation, which has been related in the pathogenesis of late-onset diabetic complication like neuropathy, retinopathy and nephropathy.[2–3]. The gene discussed is AKR1B1; the disease is kidney disorder.