This episode covers one half of the 2008 Nobel Prize in Physiology or Medicine, which was awarded to Harald zur Hausen. The Nobel Assembly at the Karolinska Institute chose to give zur Hausen the award “for his discovery of human papilloma viruses causing cervical cancer”. Topics include the use of Pap smears to screen for cervical cancer, zur Hausen’s discovery of HPV DNA in cervical cancer cells, and the development of highly effective HPV vaccines.