erythropoietin [also called EPO]
(eh-RITH-ro-POE-et-in)
This is a chemical that stimulates the production of new red blood cells. It is made in the kidney. If EPO levels are low, then the number of red blood cells is reduced (a condition called anemia). Anemia can be a side effect of some breast cancer treatments.
Audio contributed by: Marisa Weiss, M.D.