Erythropoietin (EPO) is a glycoprotein hormone created by the kidney when there is hypoxia and is the key controller of red blood cell production. EPO is associated with all periods of erythroid growth, and has its main impact at the stage of erythroid precursors. After EPO binds to its cell surface receptors, it actuates signal transduction pathways that meddle with apoptosis and activates erythroid cell proliferation.
Erythropoietin is a growth factor hormone that basically stimulates the production of red cells. Erythropoietin receptors are found on the surface of many tumor cells.