Johannes Fibiger born in Denmark in 1867 died in 1928 from a cancer of the colon. First interested in bacteriology he became later (1900) professor of pathological anatomy. His chief work on the alleged cancerigenous role of a nematode Gonglyonema neoplasticum in some species of rats allowed him to receive the Nobel Prize in medicine in 1926. The difficulties met later (species of Gongylonema spp. from rats, dietary, lack of vitamin A) and even the impossibility to reproduce his results have brought a contestation of his work. However the cancerigenous action of some parasitic heminths such as Schistosoma is now recognized.