The function of Ensembl gene identifier ENSG00000168275 (COA6, cytochrome c oxidase assembly factor 6) is as follows. Involved in the maturation of the mitochondrial respiratory chain complex IV subunit MT-CO2/COX2. Thereby, may regulate early steps of complex IV assembly. Mitochondrial respiratory chain complex IV or cytochrome c oxidase is the component of the respiratory chain that catalyzes the transfer of electrons from intermembrane space cytochrome c to molecular oxygen in the matrix and as a consequence contributes to the proton gradient involved in mitochondrial ATP synthesis. May also be required for efficient formation of respiratory supercomplexes comprised of complexes III and IV. {ECO:0000269|PubMed:24549041, ECO:0000269|PubMed:25959673, ECO:0000269|PubMed:26160915}.