 Bettini and German sprinter Erik Zabel were among the most prominent riders to quit after this season, while Mario Cipollini made a brief comeback in the early months of the year.Despite even tighter controls and warnings concerning doping, and the introduction of the blood passport by the UCI, several major races, including the Giro and Tour were faced with positive tests.In addition, the ongoing feud between the UCI and the race organizations almost came to a definite break in March, when the UCI threatened to suspend riders participating in ASO's Paris–Nice.