PRDX4 is an antioxidant enzyme and belongs to the peroxiredoxin (Prdx, Prx, or TrxPx) family. This protein is localized to the cytoplasm. Peroxidases of the peroxiredoxin family reduce hydrogen peroxide and alkyl hydroperoxides to water and alcohol with the use of reducing equivalents derived from thiol-containing donor molecules. This protein regulates the of the transcription factor NF-kappaB in the cytosol by a modulation of I-kappa- B-alpha phosphorylation.