Supporting the idea that fragmented mitochondria drive a change to a more glycolytic form of metabolism, it has been observed in hepatocellular carcinoma cells that fragmentation of mitochondria—via ablation of MFN1—reduces the oxygen consumption rate:extracelluar acidification rate (OCR/ECAR ratio) (Zhang et al., 2020). Here, MFN1 is linked to hepatocellular carcinoma.