Immune response to tumour antigens.

In experimental tumour systems in a wide variety of species there is clear evidence for the existence of immunity mechanisms directed against the elimination of the tumour. This is particularly true when the tumours are those induced either by carcinogens or by viruses. With spontaneously arising tumours in animals, specific immune responses to tumour antigens have been more difficult to demonstrate. Nonetheless these experimental systems do show that tumour antigens exist and that tumour growth can be controlled by immune responses to them. Since the immune system is the natural mechanism of control, one hopes that, when more is understood about the nature of tumour antigens on human tumours, we shall be in a position to apply some of our basic experimental knowledge to the immunotherapy of cancer in man.