EDN1 and Stroke: ESA treatment targeting a higher vs. a lower hemoglobin level is associated with a higher risk of stroke, hypertension, and vascular access thrombosis in CKD patients [25], a phenomenon possibly attributable to increased cytoplasmic Ca2+ concentrations and increased endothelin-1 production in a context of reduced nitric oxide bioavailability [26] like in CKD [27].