– Peroxiredoxin-4 (PRDX4) is a member of the AhpC/TSA family. PRDX4 is a cytoplasmic protein and contains one thioredoxin domain. PRDX4 exists in homodimer or heterodimer with PRDX1. PRDX4 reduces hydrogen peroxide and alkyl hydroperoxides to water and alcohol with the use of reducing equivalents derived from thiol-containing donor molecules. In addition, PRDX4 is probably involved in redox regulation of the cell, regulating the activation of NF-kappa-B in the cytosol by a modulation of I-kappa-B-alpha phosphorylation.