“…In lower animals, a clear relationship between viruses and cancer has been established. The carcinogenic effect of adenoviruses type 1 (Miller et al, 1970), type 1 2 (McLeod and Ham, 1963;Rabson, Kirschstein, and Paul, 1964;Trentin et al, 1962) and type 18 (McLeod and Ham, 1963) together with polyoma and simian virus has been reported (McLeod and Ham, 1963). In the hamster, the simian vacuolating virus 40 (SV40) has been shown to produce carcinoma of the prostate in vitro (Paulson, Rabson, and Fraley, 1968).…”