Among the 47 differentially expressed proteins between DN patients and patients with diabetes, phosphorylated aquaporin-2 [p-AQP2(S256)] and phosphorylated glycogen synthase kinase-3β [p-GSK3β(Y216)] were initially verified, suggesting their potential as biomarkers of diabetic nephropathy [93]. This evidence concerns the gene AQP2 and diabetic kidney disease.