For analysis of PpIX levels, tumors were harvested, embedded for frozen sectioning, and analyzed on a Leica confocal microscope as described (15 (link)). Standard hematoxylin-and-eosin staining was done on formalin-fixed/paraffin-embedded tissues, and immunohistochemical staining was performed as described (23 (link)). Sources and dilutions of antibodies were: Active caspase-3 (BioVision, Mountain View CA; 1:50), ferrochelatase FC (1:100), E-Cad (Santa Cruz Biotechnology, 1:100), Ki67 (NeoMarkers, Fremont, CA; 1:250), GAPDH (Santa Cruz Biotechnology; 1:100), TNFα (BioXcell, 1:100), CY3 or FITC-conjugated Donkey anti-rabbit (Jackson ImmunoResearch; 1:1500). To assess cell proliferation in vivo, EdU (5-ethynyl-2’-deoxyuridine) was injected (100 µg /mouse, i.p.) 1 hour prior to sacrifice. Formalin fixed tissues were sectioned and incubated with the Click-iT® reaction cocktail per manufacturer's instructions (Invitrogen, Carlsbad, CA). To estimate cell death, the TUNEL assay was performed on paraffin sections as directed by the manufacturer (Roche Applied Science, Indianapolis, IN).