CSF2 and neoplasm: Activation of MO/MAs by GM-CSF and IFN-γ might enhance antitumor activity, but might also secrete products that are proangiogenic or contribute to growth and metastasis[56,57] However, one might speculate that, as tumor burden decreases during chemotherapy, activated MO/MA might be polarized more towards antitumor effects as they are released from the influence of the tumor.