Comment by hinkley
Huh. I assumed this was going to be a collision of acronyms but erythropoietin is the same EPO used medicinally to treat anemia and abused by several generations of endurance athletes (complications include strokes and heart attacks from blood clot).
It’s a stress-signaling hormone produced by the kidneys when they detect hypoxia and triggers more red blood cell production in bone marrow.
What makes this mildly funny, though I admit in quite poor taste, is the fact that Armstrong did indeed suffer of cancer to which he lost a testicle before his comeback to win multiple Tour de France back to back. So theoretically his EPO positive results could be attributed to those tumors producing it, if this research is to be believed. Maybe not all of the times though.