ABSTRACT
Although various immunologic approaches to the treatment of cancer have been used for over a century,1 it is only relatively recent that specific human cancer targets have been defined allowing specific therapy against them. Burnet2 proposed a theory of immunosurveillance almost 30 years ago, postulating that the immune system is constandy surveying the internal milieu for cells with changes characteristic of malignancy. The next decade provided good evidence that this might be the case for malignancies related to viral infections, but for the majority of human tumors viruses are not believed to be implicated and the theory fell into disfavor in subsequent years.
