TNF and cancer: After measuring the size of tumor mass, the amount of cytokine at the site and density of infiltrating macrophages in cancer mass, it was observed that animals that received IL-17 exogenously exhibited greater tumor size, increased number of infiltrating macrophages in mass, greater amount of vascular endothelial cells, increased expression of VEGF (vascular endothelial growth factor), metalloproteinases 9 and 2, and TNF, as compared to the control group that received saline [33].