Immunologic activation of murine leukemia viruses

We propose that neoplasms of lymphoid tissue arise, not as a result of immunosuppression, but as a consequence of immunostimulation. Evidence from experimental models and clinical findings is marshalled in favor of this idea. Unchecked immunostimulation may lead to activation of latent oncogenic viruses, which in turn transform lymphoid cells to a malignant state. The feedback control of the immune response may keep the activation mechanism in check; if this is so, deregulation of the immune response would favor activation of oncogenic viruses and hence the development of malignant lymphoproliferative diseases.