Figure 4

Model for macrophage potentiation of normal mammary gland development and for tumor progression. CSF-1/chemokines produced by the TEB or tumor regulate infiltration and activity of macrophages. These cells release growth factor remodeling signals and angiogenic factors that promote vascularization and/or invasion of mammary epithelial or tumor cells through the matrix. Ang, angiopoietin; EGF, epidermal growth factor; MMP, matrix metalloproteinase; TNF, tumor necrosis factor; uPA, urokinase plaminogen activator; VEGF, vascular endothelial growth factor.