,16 In an analysis of 115 patients with various rare, hereditary, hemolytic anemias (including PK deficiency), erythropoietin, erythroferrone, and soluble transferrin receptor (sTfR) values were substantially increased in all cohorts compared with healthy controls, and hepcidin values were generally suppressed in all patients with hereditary hemolytic anemias compared with healthy controls.20 The gene discussed is EPO; the disease is pyruvate kinase deficiency of red cells.