zur Hausen H et al. – The available data are compatible with the interpretation that a specific beef factor, suspected to be one or more thermo–resistant potentially oncogenic bovine viruses (e.g. polyoma–, papilloma–, or possibly single–stranded DNA viruses) may contaminate beef preparations and lead to latent infections in the colorectal tract. Preceding, concomitant or subsequent exposure to chemical carcinogens arising during cooking procedures should result in increased risk for colorectal cancer synergistic with these infections. [more...]