This episode covers the 1926 Nobel Prize in Physiology or Medicine, which was awarded to Johannes Fibiger. The Nobel Assembly at the Karolinska Institute chose to give Fibiger the award “for his discovery of the Spiroptera carcinoma”. This Nobel Prize has been called one of the biggest blunders made by the Karolinska Institute. Topics include Fibiger’s discovery of a roundworm he claimed caused cancer, how that claim was later shown to be false, and the importance of reproducibility in science.