ENDOG and cancer: The de-regulation of apoptosis is involved in many types of cancers, including GBM, and it is tightly connected with Bcl-2 family proteins, which are localized in the mitochondrial membranes, and are able to block the release of the calcium stores in the cytosol, controlling also the release of cell death factors, as well as Apoptosis-Inducing Factor and endonuclease G. Furthermore, Bcl-2 family regulates mitochondrial ROS production, cancer cell invasion and metastasis56.