Recombinant human EPO (rhEPO) and its derivatives with prolonged half‐lives, darbepoetin alfa (hereafter termed “darbepoetin”) and polyethylene‐glycolated rhEPO, are collectively termed erythropoiesis‐stimulating agents (ESAs), and are standard treatments for anemic patients with CKD that reduce the need for blood transfusions.19 The gene discussed is EPO; the disease is chronic kidney disease.