Viruses and tumours--an update.

In the 40 years since the publication of the article by Harris (Eur J Cancer 1965, 1, 183-188), considerable progress has been made towards the understanding of the contribution of infectious agents to the development of tumours. It is estimated that 15-20% of human malignancies may have an infectious aetiology. This article attempts to summarise the current level of our knowledge with respect to tumour-associated viruses, and to place this in the context of the earlier article by Harris (Eur J Cancer 1965, 1, 183-188).