Figure 4.

Epidermal growth factor receptor (EGFR) expression and activation is detected in tumor nodules with an incomplete response to intrathoracic PDT. Levels of total EGFR (tEGFR) and phosphorylated EGFR (pEGFR) were identified by immunohistochemistry. Insets depict fluorescence of red fluorescence protein (RFP) that identifies tumor cells. Disease was identified by bioluminescence imaging after intrathoracic PDT (treatment at 150 mW/cm, 1 mg/kg HPPH). Images represent an area of 1.7 mm × 2.6 mm (photographed at 10× magnification).