Fig 1: Immunohistochemical staining of plasmin with nuclear fast red counterstaining. Forearm skin biopsies were cryo‐sectioned (7 μm) and acetone‐fixed. The sections were incubated with a biotinylated rabbit polyclonal antibody to plasmin (Abcam Cat# ab48350; Cambridge, UK, RRID:AB_882071). The primary binding was visualized using ImmPACT™ SG HRP substrate (Vector Laboratories, Peterborough, UK). Plasmin is exclusively localized in the stratum corneum and upper stratum granulosum (black–blue staining). Cell nuclei are in pink/red. Scale bar = 200 µm. Courtesy Victoria Newton, University of Manchester, UK.