Immune privilege is extended to allogeneic tissues placed into the anterior chamber of the eye and results in part from the induction of anterior chamber-associated immune deviation (ACAID)--a condition in which the host is capable of making humoral antibodies and cytotoxic T cells specific for the antigens in question, but is selectively suppressed in its capacity to generate delayed-type hypersensitivity (DTH). Privilege is extended only transiently to tissue differing at the major histocompatibility complex; by contrast, privilege is complete for tissues offering multiple minor H incompatibilities, but no MHC disparity. During examination of host responses to tumor cell lines in this latter category, it was observed that privilege was extended to all histologic categories of tumors examined except T cell lymphomas. Moreover, the capacity of minor H incompatible tumors to maintain immune privilege and sustain prolonged survival within the anterior chamber could be abrogated if T cell lymphomas were placed into the anterior chamber of the contralateral eye. Thus, T cell lymphomas exert a systemic influence which robs the anterior chamber of its immune privilege. It is concluded that this systemic effect is intimately related to lymphokines produced by T cell lymphoma allografts. Since immune privilege seems to be a physiologic property of the anterior chamber, it is suspected that local features within this site conspire to insure that antigens placed therein interact with the immune system in a manner that bypasses lymphokine production, thus allowing for the induction of ACAID and selective suppression of DTH.