However, the clinical use of the EPO-based medicines is limited due to the pleiotropic nature of this cytokine, leading to serious adverse reactions, such as arterial hypertension, cerebral convulsion/hypertensive encephalopathy, thrombo-embolism, iron deficiency, development of pure red cell aplasia, and the possibility of cancer progression [8,22,23]. The gene discussed is EPO; the disease is cancer.