Now the whole world of sports is divided into 2 parts. 1. Those who take dope secretly (such as Russia ), and 2. Who makes the dope through TUE's. And if the first catch, the latter getting the advantage of "legitimate". I can't imagine what hurt the Williams sisters, that they can take as many hard drugs. The participants of the Paralympics should be more healthy people. In addition, recent history with Dr. Brown and Salazar showed that diagnoses can be set just so important in time and correctly issue TUE's than many strong athletes (as Phelps, Williams, Norwegian biathletes and cross-country skiers) are. I believe that if the drug is in the black list WADA, that under no pretext can't be used. If a person is sick and can't compete without these drugs, then it has no place in sport.