In recent years, it has become apparent that immunoregulatory processes influence cancer development. The key players in tumor progression are mainly present in the microenvironment of the tumor and the draining lymph nodes. Interventions aimed at shifting tumor-promoting actions toward effective tumor-eradicating immunity are thus foremost required locally. As immune-modulating therapy has been shown to cause many adverse side effects when administered systemically, we strongly advocate the further development of local treatment for cancer immunotherapy. Copyright © 2012 UICC.