A group of fan joke with a fake syringe reading EPO during the 17th stage of the 94th Tour de France cycling race between Pau and Castelsarrasin, 26 July 2007. AFP PHOTO / JOEL SAGET (Photo credit should read JOEL SAGET/AFP/Getty Images)
Day 157 has 88 protein-coding genes (browser view) including EPO (erythropoietin).
Erythropoietin is produced by the kidneys and is a hormone signal to the bone marrow to produce more red blood cells. As a drug, it is used to treat anemia, but also illicitly as a performance-enhancing drug in cycling (although it may not actually help.)
Click here to see all 8386630 letters of Day 157