How would today's athletes try to dope their genes? They'd probably start by choosing the one they'd like to add or alter. For bigger or stronger muscles, they might inject a gene for making testosterone, human growth hormone or a muscle-strengthening protein called IGF-1, which stands for insulinlike growth factor-1[source: Friedmann, Wells]. To boost endurance, runners or cyclists might be tempted to try to add genes for erythropoietin, which would circulate more oxygen-carrying cells in the blood [source: Wells]. At their own risk, sports self-engineers could choose from close to 200 genes linked to athletic performance [source: Rankinen].
After selection, comes acquisition. In the United States, this is where the operation turns illegal. The U.S. Food and Drug Administration (FDA) hasn't approved any human gene products for sale [sources: Oak Ridge National Laboratory, Friedmann]. The only way you can inject genes into a living, breathing organism is through an experiment -- and only after clearing much red tape. Animal experiments must be approved by a university or hospital ethics committee. Human experiments also must be approved by the National Institutes of Health and the FDA. Currently, only humans with serious illnesses can be injected with genes as part of a clinical trial. No other uses are allowed.
Rules aside, athletes have asked scientists for gene injections that have desirably revamped the bodies of patients or mice, even offering bribes [source: Reynolds]. So far, scientists have refused because of regulations and ethical concerns [source: Reynolds].
What concerns officials, says gene doping expert Friedmann, are laboratories that could be paid to prepare the genes. "If someone were to offer a well-trained scientist, two or three post-doctoral fellows and a technician money to buy some equipment, set up a laboratory somewhere and make a virus that expresses this or that gene, that can be done quite readily," he says. "The money would be easily available through sport." Instructions for preparing and delivering the genes are published in scientific journals. "Technically, it's not beyond the capability of many tens of thousands of laboratories around the world," Friedmann says.
The Internet could be another source of ready-made genes. Some Web sites claim to sell Repoxygen, a drug that contains the human gene for erythropoietin, plus some DNA controlling how it's made, housed inside a virus [source: Frankel]. Developed by a U.K. lab to treat anemia, Repoxygen caught the eye of Thomas Springstein, a German track coach, who, according to court records, tried to get the product for his athletes [source: Reynolds].
An athlete might scout around in China, too. Before the Beijing Olympics, one incident showed how a gene-doping substance might change hands. A German television reporter posing as swimming coach went to a Chinese hospital, asked about gene doping and was offered injections of stem cells, which, by WADA's definition, are gene-doping agents [source: Klein]. But the hospital doesn't seem to have offered either stem cells or genes to any real athletes [source: AP].
If an athlete managed to get genes to inject, he or she would need someone to inject them -- a crooked coach, teammate or doctor -- and because of the medical risk, monitor him or her for side effects.
Read on to learn how the athlete might be caught.