Fig. 1
From: New insights into M1/M2 macrophages: key modulators in cancer progression
Origination and maturation of macrophages. Resident and recruited macrophages are derived from YCPC, BMDC, as well as from circulating monocytes. CSF plays crucial role in macrophages origination. Macrophages in tumor zone intimately interact with tumor cells, thereby undergoing phenotypically polarization to extremely M1 (due to the effect of IFN-γ, TNF-α and LPS, et al.) and M2 (due to the effect of IL-4, IL-10, TGFβ-1 and PGE2, et al.)