In this book, the authors present topical research in the study of the biochemical characteristics, functions and potential applications of peroxidases. Topics discussed include the unique properties and biotechnological potential of ligninolytic peroxidases; the functions and regulation during pathogenesis of plant peroxidases; phospholipids and peroxidases in mitochondrial apoptosis; glutathione peroxidases in stem, cancer, and cancer stem cells; biochemical responses of aquatic macrophytes to two abiotic stresses; role of ascorbate peroxidase in antioxidant protection; and the route, dose and duration of exposure to cadmium-relevance to oxidative stress induction.