Abstract
Lines of Syrian hamster lung and liver cells originally exposed as primary cultures to large doses of SV40 exhibited increased growth rate, high plating efficiency, morphological transformation, and, in some instances, oncogenic potential after unusually long intervals. In at least 2 lines acquisition of oncogenic potential occurred independently of morphological transformation. In none of a total of 11 cell lines studied in detail was conclusive evidence for the presence of the SV40 genome obtained.