Anti-VP antibodies are used in antigen-specific immunodetection in biological samples. The target VP is a known alias name of the protein protoporphyrinogen oxidase, encoded by the PPOX gene in humans. This 477-amino acid residue protein is known to catalyze the 6-electron oxidation of protoporphyrinogen-IX to form protoporphyrin-IX. It is localized to the mitochondria of the cell. In terms of tissue expression, it is found to be expressed in the heart, brain, placenta, lung, liver, skeletal muscle, kidney and pancreas.