Interestingly, a recent observation added new evidence of UA as antioxidant acting to protect the endothelial function, as patients with renal hypouricemia (<2.5 mg/dL due to SLC22A12/URAT1 loss-of-function mutations) present a marked reduction of flow-mediated dilation [72]. Here, SLC22A12 is linked to hypouricemia, renal.