These findings are also reminiscent of pharmacokinetic experiments in which distribution of EGF conjugated to Cy5.5 fluorophore was measured in mice with breast cancer xenografts [21], with experiments of confocal endomicroscopy targeting EGFR with fluorescently labeled antibodies [44] and with our previous study using HT-29 orthotopic tumors visualized with EGF-NIR [8]. Here, EGFR is linked to breast carcinoma.