However, as we found that predicted EGFR ligand concentrations were essentially similar in HCS3/EGFR-GFP flank xenografts harvested 1–5 weeks old after implantation and within the range of tumor volumes of 100–700 mm3 (data not shown), such deviations are unlikely to significantly elevate ligand concentrations. This evidence concerns the gene EGFR and neoplasm.