MFN1 and breast cancer: Interestingly, this trend was also found using frequently studied breast cancer cell models, where in comparison to non-metastatic breast cancer cells (MCF-7), metastatic breast cancer cells (MDA-MB-231 and MDA-MB-436) had more fragmented mitochondria correlating with higher protein expression of pS616-DRP1 and DRP1, and decreased MFN1 (Zhao et al., 2013).