The M1 macrophages produce pro-inflammatory factors (TNF-α, IL-1β, and iNOS), chemokines (CXCL10, CXCL11, and CCL2), antigen-presenting molecules such as MHCII, costimulatory molecules (CD86 and CD80), and antigen-treated peptidases, which play an anti-tumor role in cancer. Here, CCL2 is linked to cancer.