Testosterone injections are among the most common performance-enhancing drugs detected in athlete screenings, but some lucky competitors can take them without fear of exposure, the New York Times reports. Of 55 men given testosterone in a recent study, 17 came up clean on a drug test because they're missing the pair of genes that cause testosterone to dissolve in urine.
Almost 10% of Caucasians are missing the genes, as are a whopping two-thirds of Asians. “It’s disturbing,” said one anti-doping researcher. “Basically, you have a license to cheat.” While it has long been known that some, especially Asians, were able to flout the tests, the cause has just been discovered. Some are now wondering if athletes should be forced to submit DNA samples with tests.