Indeed, we found during our mechanistic validation that TNF signaling takes a central role in controlling endothelial VEGF production and angiogenic maladaptation and that the TNF-α/sTNF-R1-ratio in uremic patient serum is indicative of endothelial dysfunction with its clinical relevance for the design of HD filters and adjunct optimal care in RRT (8, 20, 24, 27, 30, 38–41). Here, TNF is linked to endothelial dysfunction.