Compared to Sham, the CHF group also had an altered gastrocnemius mitochondrial fission and fusion marker balance, with a lower ratio of the fusion OPA1 to fission DRP1 protein levels, mainly due to low OPA1 protein content with comparable DRP1 (Figure 2A–C), suggesting higher mitochondrial fragmentation. The gene discussed is OPA1; the disease is congestive heart failure.