Macrophages undergo a wide spectrum of polarized activation states, and have the potential
both to elicit tumor and tissue destructive reactions and to promote tumor progression
(macrophage balance). In general, tumor-associated macrophages (TAM) from established
tumors and the related myeloid-derived suppressor cells are diverse and have properties of
M2-activated cells. As such, they help cancer progression and metastasis. Therefore, TAM
are a key component of pathways connecting inflammation and cancer.