KDR and hyperhomocysteinemia: Coagulation-related genes, hyperhomocysteinemia-related methylene tetrahydrofolate reductase (MTHFR) gene, transforming growth factor-b1 (TGFB1), matrix metalloproteinases (MMPs), hypoxia inducible factor-1α (HIF1A), heme oxygenase-1 (HO1) and vascular endothelial growth factor-A (VEGFA) and its receptors (FLT1 for VEGFR-1 and KDR for VEGFR-2) have all been studies for their association with AVF stenosis or thrombosis.