Phenotypically and functionally distinct T-cell subsets in anti-tumor responses.

Helper T cells and cytolytic T cells have both been implicated in tumor cell rejection in vivo but their roles and relative importance are still controversial. Here, Toshiyuki Hamaoka and Hiromi Fujiwara discuss recent experiments which suggest that tumor cell growth can be inhibited nonspecifically by the action of gamma interferon as well as by cytolysis and that immunized cells of both 'cytotoxic cell' and 'helper cell' phenotype can produce this lymphokine.