SDC1 and chronic kidney disease: In a further rat model of CKD established by subtotal nephrectomy (SNx), which well mimics human pathology, Sdc4 was the highest expressed syndecan in fibrotic kidneys, increasing in parallel with the loss of kidney function and peaking at a level of advanced fibrosis, when the process becomes irreversible [63], confirming a clear involvement of Sdc4 in CKD.