Formalin-fixed paraffin-embedded mouse lung tissue was used for staining with AOX antiserum (1:2000; custom raised in rabbit; 21st Century Biochemicals, Marlborough, MA, USA) (42 (link)), visualized using the ZytoChem Plus (HRP) Polymer Bulk Kit (Zytomed Systems GmbH, Berlin, Germany) and VECTOR NovaRED Peroxidase (HRP) Substrate Kit (Vector Laboratories, Burlingame, USA).