FIS1 and Sepsis: While levels of mitochondrial fusion-related genes Opa1 and Mfn2 were not different between groups, levels of mitochondrial fission-related genes, Fis1 and Dnm1l, were increased in Sepsis by 16% (p = 0.0197) and 42.1% (p = 0.0416), respectively (Fig. 3G).