atomic force microscopy (afm) revealed the presence of vdac1 monomers as well as dimers and larger oligomers showcasing the interaction of the pore with itself, however, dimers are more frequent. hvdac1 in particular has been shown to arrange in parallel dimers leading to increased permeability of the pore. the glutamate located at the 73rd position on vdac1 has also been shown to play a role in oligomerization when in the presence of calcium. vdacs can also oligomerize to form part of the mitochondrial permeability transition pore (mptp) and, thus, facilitate cytochrome c release, leading to apoptosis. vdacs have also been observed to interact with pro- or antiapoptotic proteins, such as bcl-2 family proteins and kinases, and so may contribute to apoptosis independently from the mptp.