Immunotherapeutic suppression in transplantable solid tumours

α-FOETOPROTEIN (AFP) is a glycoprotein, of unknown function, synthesised by the foetal liver and yolk sac of mammals¹. Increased serum levels of AFP in adults are indicative of either pregnancy or a pathological state, that is primary hepatocellular carcinoma, regenerating liver and teratoblastomas of the ovary and testis^2,3. Recently, abnormal levels of AFP in amniotic fluids have been correlated with foetal distress ⁴. While attempting to study the physiological role of AFP during ontogenic and oncogenic growth, we have observed an interaction between AFP and its homologous antiserum that may have immunotherapeutic value. We report here the suppression of mouse hepatoma growth in vivo and in vitro using passively administered antiserum to AFP.