Regulation of the Macrophage Content of Neoplasms by Chemoattractants

Abstract
Factor chemotactic for mononuclear phagocytes was found in supernatant fluids of cultured human and mouse tumor cells. In 11 mouse tumors there was a correlation observed between chemotactic activity and macrophage content of neoplastic tissues. Tumor-derived chemoattractants appear to participate in the regulation of tumor-associated macrophages.