Fig. 1

Tumor growth by 13 days with TEM and M1 and M2 macrophage subtypes present. Top left: Tumor with proliferating regions in red and quiescent in blue. Vessels here are shown as black lines, with preexisting vessels comprising the grid space and angiogenic vessels depicted as irregular offshoots. Top center: Oxygen gradient, showing hypoxic conditions in the tumor interior. Top right: Macrophage chemoattractant, (e.g., tumor angiogenesis factors) secreted by the hypoxic tissue of the tumor. Middle left: Monocytes extravasated from the vasculature. Middle center: M1 macrophages shown in red. Middle right: M2 macrophages shown in red. Bottom l eft: TEMs shown in red with vasculature superimposed in gray. The Angiopoietin-2 secreted by the vasculature has caused the TEMs to cluster around the neoangiogenic sprouts. Bottom center: IL-10 secreted by the TEM, which favors monocyte differentiation into M2. Bottom right: Angiopoietin-2 secreted by the neovasculature, which attracts the TEMs to accumulate by the vessels. Each panel represents 4 mm²