A recent Review Article from Prof. Gerrit J. Poelarends and PhD student Marie-Cathérine Sigmund on peroxygenases has been published in the September issue (Vol 3, September 16, 2020) of Nature Catalysis. Peroxygenases are promising enzymes to contribute to more environmentally friendly and sustainable oxidation reactions in industry. The Review Article gives a comprehensive overview of enzymes with peroxygenase activity and summarizes diverse strategies, including directed evolution, rational approaches and the assistance of small functional molecules to improve the expression, catalytic activity, substrate scope or selectivity of these enzymes. Furthermore, the exploration of modified or unnatural cofactors to design artificial peroxygenases for desired reactions is discussed.