Apoptosis induction after mTHPC-PDT was also observed via Annexin V-FITC/PI staining by Marchal and colleagues in HT29 human adenocarcinoma cells (1.5 μM, 1.92 J/cm2) [49] and Abdulreham et al., who found apoptotic populations in colon carcinoma cell lines SW480 and to a lesser extent in SW620 with no evidence of late-apoptotic or necrotic cells (0.2–11.8 μM, 6.0 J/cm2) [35]. This evidence concerns the gene ANXA5 and colon carcinoma.