IS has been reported to be excreted from kidney under normal renal function conditions; however, IS accumulates in the kidney when renal function is decreased, and CKD progresses because of the activation of NADPH oxidase and overproduction of ROS in mesangial cells and renal proximal tubular cells.22 We found that a DHA-containing diet could attenuate IS accumulation in the kidney after nephrectomy. The gene discussed is FMO5; the disease is chronic kidney disease.