And while EPO's effect is long-lasting, the hormone itself rapidly disappears from the body.

BBC: Starting blocks

It says the European Patent Office (EPO) has shown itself willing to grant thousands of software patents - and worries the EU could end up with a system in which appeals against such judgements are decided according to the EPO's own rules.

BBC: European Parliament in Strasbourg

If it hasn't, it should be classed as suspicious because the use of artificial EPO for doping causes the body's own production to shut down.

BBC: Concerns over Olympic drug test

Newer tests that may pick up EPO use can not detect Aranesp, Amgen's newer, longer-lasting version of the protein.

FORBES: Magazine Article

Eprex, Roche's NeoRecormon and Amgen's Epogen are all versions of the same hormone, erythropoietin, or EPO.

FORBES: Magazine Article

The new test is the latest weapon in WADA's arsenal following the development of tests for the endurance-boosting drug erythropoietin (EPO) and so-called designer steroids such as tetrahydrogestrinone (THG), which have been chemically engineered to deceive the testers.

CNN: Anti-drugs chief confirms HGH test

"First of all, we have to go for the urine testing, now we have to go to EPO - I said to the ATP that I don't think it's correct, but they really didn't listen, " Safin said.

BBC: Safin in race for fitness