OPA1 and neoplasm: In one study, MDA-MB-231 cells were injected into mice; when the mice were treated with mitochondria, there was a decrease in tumor weight/volume, decrease in proliferation, and increase in apoptosis; there was also an increase in fusion proteins, mitochondrial dynamin-like GTPase (OPA1) and mitofusin 2 (MFN2) and a reduction in fission protein dynamin-related protein 1 (DRP1) [37].