EGFR and colonic neoplasm: To further establish this bio-imaging approach we focused in the present study on the cell line COLO205 which expresses low levels of EGFR and compared it to the human epithelial squamous carcinoma A431 cell line expressing high levels of EGFR as well as clinical samples, taken during tumor resection of colon cancer and normal colon tissues with heterogeneous expression of EGFR.