CCL5 and neoplasm: In collaboration with Th1 cells, they effectively inhibit tumor progression by producing nitric oxide (NO) and reactive oxygen species (ROS).459 Chemokines produced by M1 macrophages, such as CCL5, CXCL9, and CXCL10, also recruit activated T cells and NK cells to exert anti-tumor immunity.460 Therefore, M1 polarization of macrophages is critically important in anti-tumor immunity.