Figure 2.

Signaling and the secreted factors of M2-TAM to promote cancer invasion and metastasis. The signaling molecules of M2-TAMs that modulate cancer cell migration, invasion, and metastasis through activation of phosphatidylinositol 3-kinase/human protein kinase B (PI3K/Akt) or ERK, either of which leads to upregulation of epithelial–mesenchymal transition (EMT) regulators, including Snail and Slug. Abbreviation, IL-6: interleukin-6; EGF: epithelial growth factor; EGFR: EGF receptor; MMP9: matrix metalloproteinase 9; VCAM-1: vascular cell adhesion protein-1; TF: transcription factor.