Hamamoto et al (1) were able to demonstrate that combination therapy of a lung tumor by using radiofrequency ablation (RFA) with local injection of an immunostimulant, OK-432, resulted in improved survival when compared with other therapies tested in a VX2 rabbit model. In addition, not only was greater tumor regression seen in a second distant ear tumor implanted prior to the therapy, but also reduced tumor growth was seen when a second tumor implantation (ie, rechallenge) was attempted. These factors strongly suggest the successful activation of systemic antitumor immunity using this approach in this specific tumor model.