Genetically determined resistance mechanisms in leukemia

It now seems unlikely that the theory of immunologic surveillance can satisfactorily explain how neoplasms arise from a nidus of transformed cells. The development of neoplasms is a multistage process, with one or more genetic controls at each step. Immunologic factors constitute only one, perhaps minor element, in the pathway. In the case of viral oncogenesis, immunologic surveillance exists, but as a special case of antiviral immunity. Susceptibility or resistance to leukemia viruses in mice may hinge on the action of a single gene. Such a gene may exert controls that are completely unrelated to the immune system. Thus leukemia can develop in an immunologically 'normal' individual who possesses atypical viral genetic information.