PODXL and diabetic kidney disease: So far, many studies have identified candidate biomarkers in urine proteome for early diagnosis and prediction of DKD progression, mainly including biomarkers reflecting renal injury caused by glomerular injury, podocyte injury, renal tubular injury, oxidative stress, inflammation, and activation of the renin-angiotensin system (RAS), such as transferrin related to glomerular injury protein, type IV collagen (IV), podx protein (podxl), and wilmstumor-1 factor related to podocyte injury.