Figure 8.

Proposed model. As described, omental immune aggregates contain mesothelial cells, some of which are hypoxic (red) and therefore secrete VEGF-A (black asterisks). In a normal physiological setting (top), VEGF-A production can stimulate blood vessels to produce vascular sprouts (green outlined in red), resulting in the induction of angiogenesis and recovery of once-hypoxic mesothelial cells. The increase of vessels delivers more immune cells, along with additional oxygen and nutrients necessary to support the influx of cells. In a metastasis model (bottom), tumor cells invade aggregates and co-opt the existing dense vasculature. Because angiogenesis is already induced, new blood vessel formation is rapid, resulting in aggressive tumor growth.