MFN1 and cancer: Herein, ARK5-WT cells demonstrated mitochondrial fission and higher phosphorylation of DRP1 [37, 38] at serine 616 (DRP1S616), and lower expression levels of MFN1, MFN2, and OPA1 (Fig. 5B), similar to oncogenic RAS mutant–mediated phosphorylation of DRP1S616 and mitochondrial fission in several human cancers, such as melanoma, and breast cancers [39–41].