The use of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) is a major tool in the management of heart failure, but it may hamper the hemoglobin levels due to the effect of angiotensin II on erythropoietin synthesis and the erythroid progenitor cell production in the bone marrow [8]. The gene discussed is EPO; the disease is heart failure.