Immunization with autologous tumor cells mixed with allogeneic IL-12–producing bystander cells eradicates preestablished syngeneic lymphoma.

A20 tumor-bearing BALB/c mice were vaccinated subcutaneously on days 1, 5, 15 (A-C), and 30 (B-C) after tumor challenge. Irradiated tumor cells used as vaccine are indicated. A group of tumor-bearing mice was left unvaccinated. Tumor-free survival was evaluated over an observation period of 4 months. Fourteen mice were included in each group.