EGFR and neoplasm: Since antibodies are approximately 25-fold larger than EGFR ligands, they may not be easily transported within solid tumors, and in a different imaging strategy EGF was labeled with Cy5.5 [166] and IRD800 [167–168], available from LI-COR Biotechnology - GmbH, Bad Homburg, Germany, to study EGFR density on tumor cells.