Hypocupremia due to excessive Zn intake could be the reason for subsequent anemia and EPO resistance, as shown in the case report of a 56-year-old woman undergoing HD who developed severe anemia with hemoglobin levels between 5 and 7 g/dL despite no signs of bleeding, inflammation, or infection and despite an optimal dose of erythropoietin. This evidence concerns the gene EPO and anemia (phenotype).