NDUFAF7 is an arginine methyltransferase essential for assembling the mitochondrial NADH:ubiquinone oxidoreductase complex (complex I), a critical component of the respiratory chain. The protein functions by catalyzing symmetric dimethylation of arginine-118 (and potentially arginine-85) on the NDUFS2 subunit after it incorporates into complex I, thereby stabilizing early assembly intermediates 1. This methylation-mediated mechanism is conserved from bacteria to humans 2, with methylation promoting substrate release to regulate the assembly process. NDUFAF7 dysfunction has been implicated in multiple disease contexts. Loss of NDUFAF7 function causes rapid, protease-dependent degradation of ND1 and decreased levels of other structural subunits, resulting in complex I assembly failure 1. Germline disruption in mice is embryonic lethal, underscoring its developmental importance. NDUFAF7 variants have been identified as disease-causing in early-onset high myopia, with both pathogenic and potentially pathogenic mutations reported in affected families 34. Additionally, NDUFAF7 was identified as a mitochondria-related biomarker in childhood allergic asthma, with downregulation correlating to disease pathogenesis 5. A common variant near PRKD3/NDUFAF7 was associated with Alzheimer's disease risk in large-scale genetic studies 6. These findings establish NDUFAF7 as a critical mitochondrial assembly factor with broad clinical relevance to neurological, developmental, and metabolic disorders.