Patients with chronic renal failure experience pallor in the oral mucosa related to anemia, which may be caused by the kidneys producing less erythropoietin, renal loss of red blood cells, marrow fibrosis, and increased red cell fragility with early destruction (Patil et al., 2012, Saif et al., 2011a, Saif et al., 2011b). The gene discussed is EPO; the disease is anemia (phenotype).