Viruses and Human Cancer

Abstract

THE contention that viruses may cause cancer in man rests mainly on analogy with observations in other species, particularly laboratory animals.^{1 , 2} However, even if tumor viruses were known not to cause human cancer they would be a suitable starting place for the study of genetic mechanisms in neoplasia. Oncogenic viruses have from seven to 50 genes, only a few of which are required to confer malignancy on an infected cell. These viruses obviously represent a more promising place to search for oncogenic genes than mammalian cells, which contain two million genes or more.^{3 , 4} Approaches to Cancer VirusesViruses probably evolved . . .