Anti-cytochrome c oxidase subunit Va antibodies are used in antigen-specific immunodetection in biological samples. The target cytochrome c oxidase subunit Va is a known alias name of the protein cytochrome c oxidase subunit 5A, encoded by the COX5A gene in humans. This 150-amino acid residue protein is a known component of the cytochrome c oxidase, the last enzyme in the mitochondrial electron transport chain which drives oxidative phosphorylation. It is localized to the mitochondria of the cell. It is reported to be widely expressed in many tissue types. Other synonyms for cytochrome c oxidase subunit Va include COX, COX-VA, and MC4DN20.