Anti-caseinolytic mitochondrial matrix peptidase chaperone subunit X antibodies are used for the immunodetection of the protein encoded by the CLPX gene. In humans, the canonical protein has a reported length of 633 amino acid residues and a mass of 69.2 kDa. Its subcellular localization is in the mitochondria. It is reported to be highly expressed in skeletal muscle and heart and to a lesser extent in the liver, brain, placenta, lung, kidney and pancreas. A member of the ClpX chaperone protein family, it is known to be involved with proteolysis. The gene encoding this protein is implicated in Protoporphyria. Other names for this target antigen include ATP-dependent Clp protease ATP-binding subunit clpX-like, mitochondrial, ClpX caseinolytic peptidase X homolog, ClpX caseinolytic protease X homolog, energy-dependent regulator of proteolysis, and EPP2. Gene orthologs have been identified in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species.