The product is a growth factor produced in the kidneys that stimulates the production of red blood cells. It works by promoting the division and differentiation of committed erythroid progenitors in the bone marrow. It is a 165-amino acid erythropoiesis-stimulating glycoprotein produced in cell culture using recombinant DNA technology. It has a molecular weight of approximately 30,400 daltons and is produced by mammalian cells into which the human growth factor gene has been introduced. The product contains the identical amino acid sequence of isolated natural product and has the same biological activity as the endogenous the product.