Holy Crap Anons! I just got woke!
Blood banks give a patient their phlebotomy through prescriptions. That blood cannot get used even though the blood is rich in iron and high red blood cell count.
It gets pulled out a pint at a time for a disease called Polycythemia. It's actually cream of the crop blood but because it is medical reason withdrawn, it is not used for patients who need blood. Where does it go then?
True story:
Spouse anon with rarest blood type was diagnosed with this incurable disease and told to tell siblings so they can get started on the preemptive treatment.
Hematologist retires after a period of time and miraculously spouse anon was cured of this incurable disease after going to a new doctor and new facility. No sign of it.