Anti-CYC1 antibodies are used in the immunodetection of the protein cytochrome c1. In humans, the canonical protein has a reported length of 325 amino acid residues and a mass of 35.4 kDa. Its subcellular localization is in the mitochondria. A member of a the Cytochrome c protein family, CYC1 is a known component of the ubiquinol-cytochrome c oxidoreductase, a multisubunit transmembrane complex that is part of the mitochondrial electron transport chain which drives oxidative phosphorylation. Synonyms for this target antigen include UQCR4, cytochrome c1, heme protein, mitochondrial, complex III subunit 4, complex III subunit IV, cytochrome b-c1 complex subunit 4, and MC3DN6.