Interferons: pleiotropic cellular modulators.

Interferons play a key role in host response as pleiotropic modulators of cell function. As induced proteins, interferons contrast with other physiologic regulators such as glucocorticoids which are produced relatively continuously. Antitumor effects have been suggested to be principally the result of two mechanisms: a direct effect on the functional capacity or antigenic composition of tumor cells or an indirect effect on modulation of immunological effector cell populations with tumor specificities. Over the past decade, interferons have been established as therapeutically useful molecules for malignant and viral diseases.