COX6C encodes cytochrome c oxidase subunit 6C, a nuclear-encoded component of mitochondrial complex IV that plays a critical role in oxidative phosphorylation 1. As part of the electron transport chain's final step, COX6C contributes to the transfer of electrons from reduced cytochrome c to molecular oxygen, generating ATP through oxidative phosphorylation 1. The protein requires nuclear translation followed by mitochondrial transport to form the functional COX complex 1. COX6C expression is regulated by specific intron-dependent mechanisms, with DAZAP1 binding to its mRNA and suppressing pre-mRNA splicing efficiency, thereby controlling COX6C protein levels and mitochondrial energy production 2. Disease relevance is significant, as COX6C dysregulation occurs in multiple pathological conditions. Copy number amplification at 8q22.2 drives COX6C overexpression in lung adenocarcinoma, promoting cell proliferation through ROS-AMPK signaling and mitotic regulation 3. Conversely, COX6C downregulation is associated with missed abortion, where reduced expression correlates with decreased mitochondrial function 4. In multiple myeloma, elevated COX6C expression promotes cell proliferation by maintaining mitochondrial structure and ATP levels 5. COX6C also serves as a biomarker in sarcopenia, where decreased expression reflects mitochondrial dysfunction in age-related muscle loss 6. These findings establish COX6C as both a critical metabolic regulator and potential therapeutic target.