Hereditary alterations in tumor-host relationship

An indirect exposure of mice during their fetal stage of development to Ehrlich ascites tumor cells alters the animals' response to this tumor during their adult life. Control mice injected intraperitoneally with Ehrlich tumor cells react in various ways to the presence of this alien tissue. The response is expecially evident during the first 48–72 h post-injection. Several aspects of this complex reaction are absent in those animals which were exposed to this tumor in utero. The measurably altered reactivity toward the Ehrlich tumor cells is hereditary. Possible mechanisms of this alteration are discussed.