Recombinant human erythropoietin (EPO) is expressed in human HEK 293 cells as a glycoprotein with a calculated molecular mass of ~18 kDa. This protein is manufactured in human cells using an all-human production system, with full chemically defined ingredients and with no serum. The human cells expression system allows human-like glycosylation and folding, and often supports better stability of the protein in culture. The protein is produced with no artificial tags.

Erythropoietin (EPO) is a glycoprotein hormone, known for its erythropoietic activity. It is used as treatment for anemia in humans with renal failure or cancer. EPO also reduces the amount of blood transfusions required on premature infants and surgeries.
EPO consists of 165 amino acids and has a high carbohydrate content, of both N-linked and O-linked types. The oligosaccharide chains are responsible for EPO production, secretion, longevity, and functioning. The biological activity of EPO depends upon two disulfide bonds, one formed between cysteine7 and cysteine160, and the other between cysteine29 and cysteine33. Thus, EPO proper folding, glycosylation and disulfide bonds formation are crucial for its function.
EPO was found to downregulate HIF-1α in the diabetic rat model. EPO helped maintaining the homeostasis of intracellular zinc in retinal cells, altered as a result of diabetes, by restoring Zinc transporter 8 (ZnT8) expression.