COX6A1 encodes cytochrome c oxidase subunit VIa, a component of mitochondrial respiratory complex IV that catalyzes the final step of the electron transport chain by reducing molecular oxygen to water 1. This ubiquitous isoform is synthesized as a preprotein and its expression is regulated by conserved promoter elements including binding sites for nuclear respiratory factors 1. Beyond its canonical respiratory function, COX6A1 exhibits cytoprotective properties by suppressing Bax-induced apoptosis and reducing reactive oxygen species generation, suggesting roles in cellular stress response 2. COX6A1 mutations cause autosomal-recessive Charcot-Marie-Tooth disease (CMT), with a reported 5 bp splicing defect leading to reduced COX6A1 expression and diminished respiratory complex IV activity 3. Cox6a1-null mice demonstrated neurogenic muscular atrophy and walking difficulties, confirming the neurological importance of this subunit 3. Recent proteomic studies implicate COX6A1 in broader disease contexts: repetitive traumatic brain injury upregulates Cox6a1 as a deregulated protein linked to neurodegenerative pathways 4, while COX6A1 upregulation in lung adenocarcinoma correlates with immune escape and tumor progression 5. COX6A1 also emerged as a biomarker for oral leukoplakia malignant transformation 6. These findings indicate COX6A1 functions beyond oxidative phosphorylation, participating in apoptosis regulation and immune modulation relevant to cancer and neurodegeneration.