In 2008, the World Anti-Doping Agency officially launched the biological passport. The first validated module to operate was the blood module to fight erythropoietin (EPO) and blood transfusion abuse. It has been quite efficient to catch some doped athletes, but above all, was very good in reducing the prevalence of doping. It is unclear if athletes stopped doping or have adapted and are taking micro doses of EPO or transfusing small blood volumes. More recently, the steroid module was released, but until now, the number of urine adverse passport cases is very low.