Some aspects of the macrophage-cancer relationship

Tumor-induced immune dysfunction: the macrophage connection

“…This finding revealed the dual nature of Ms, which depending on their in vivo context can impart diametrically opposed activities. For example, although vital effectors of innate immunity, Ms may contribute up to or more than half of a tumor's mass [22] and are actually required for the tumor to survive [20][21][22]28]. To ensure survival, tumors actively recruit monocytes by producing chemotactic agents, including transforming growth factor-␤ (TGF-␤) [29] and M chemotactic protein-1 (MCP-1) [30], which promote M infiltration [21,30].…”