Fig. 2From: Improving the therapeutic efficacy of oncolytic viruses for cancer: targeting macrophagesMacrophage activation and M1/M2 typing. Macrophages polarized into classically activated (M1) or alternatively activated (M2) macrophages under the influence of different cytokines or other factors secrete different cytokines to change the cellular microenvironment to a pro-inflammatory or anti-inflammatory state, exerting anti-tumor or pro-tumor effects at the tumor siteBack to article page