CASP3 and neoplasm: A significant activation of caspase-3, which plays a central role in the apoptosis pathway, was identified in tumor cells treated with 5-ALA SDT, and an immunofluorescence analysis detected apoptotic features such as the redistribution of Bax/Bak and the release of cytochrome c after SDT, confirming the involvement of a mitochondria-dependent apoptosis pathway [32].