The Ndufs4 KO mouse is a gene knockout model created using gene-editing techniques to knock out the Exon 2 of the Ndufs4 gene (the homolog of the human NDUFS4 gene) in mice. Homozygous Ndufs4 KO mice begin to exhibit phenotypes around 3 weeks of age, rendering them unable to breed offspring. This model can be used to study the pathogenic mechanisms of Leigh Syndrome, Leber's hereditary optic neuropathy (LHON), mitochondrial encephalomyopathy, lactic acidosis, and stroke (MELAS), and some forms of Parkinson's disease, providing a research basis for developing related therapeutic interventions.