Abstract
The oncogenic effect of the virus was tested in mice of different strains and ages. Local sarcomas were induced in all mice, although strain, age or dose dependent variations were found. 4 forms of development occurred: progressive lethal; lethal but long persistent; complete tumour regression; tumour recurrence after regression. Virus activity was highest in the progressively-growing and in the recurrent tumours, while in the long-persistent tumours or in tissue at the site of regressed tumours, little or no virus could be detected.