In contrast with the ROS‐producing NADPH oxidase RBOHD, which surprisingly inhibits the spread of cell death in pathogen‐infected Arabidopsis tissues (Pogány et al., 2009), functional cell wall peroxidases PRX33 and PRX34 apparently enhance the development of necrotic symptoms triggered by infection with A. brassicicola. The gene discussed is FMO5; the disease is infection.