Figure 2: Immunohistochemical analyses of expression of VEGFA, IL-8, MMP-2, and MMP-9 in orthotopically implanted colon tumors. The parental colon cancer cell line originates from a primary human colon carcinoma. The clones were expanded, and the resulting populations were screened for production of TGFα. The microenvironment of selected high level TGFα tumors is enriched in VEGFA, IL-8, MMP-2, and MMP-9. Expression of the angiogenic proteins in tumors that do not express TGFα is significantly attenuated. Scale bars = 100 μm [50].