[Tumor induction in mice treated with hydrocortisone and innoculated with polyoma transformed hamster cells]

Tumors have been induced in hydrocortisone treated Mice innoculated with wild-type polyoma transformed Hamster cells. The filtrate from these tumors infects Mouse embryo cells and induces the production of polyoma virus. The polyoma virus has been characterised in the infected cells with anti-polyoma capsid serum.