Role of macrophages in malignancy.

Macrophages themselves are a heterogeneous mixture of cells which mediate their effects not only through phagocytosis but also through the production of various soluble factors such as cytokines and chemokines. The most important function of macrophages is the defense of the body against pathogen aggressions. However, when recruited within neoplastic tissues, tumor-associated macrophages polarize differently and do not predominantly exert their immune function but rather favor tumor growth and angiogenesis.