Voltage-dependent anion channel (VDAC) is an outer mitochondrial membrane channel protein expressed in a ubiquitous manner as it is required for proper mitochondrial function. The three isoforms expressed in higher eukaryotes are highly conserved. VDAC1, VDAC2 and VDAC3 allow the entry and exit of most metabolites in and out of the mitochondria. VDAC channels are best described for their role in apoptosis. In the early stages of the signaling pathway, a proapoptotic factor, a member of the Bcl2 family is responsible for closing the channel thereby decreasing the release of ADP and ATP from the mitochondria.