Immunohistochemistry of kidney transplants showing chronic allograft remodelling revealed a strong labelling of SERPINE1 protein expression in areas of interstitial fibrosis and vascular remodelling (black arrows in A, white arrows in B). SERPINE1 positive cells were activated fibroblasts, endothelial cells and smooth muscle cells, Figure 9 A (magnification 100×). In not fully remodelled functional compartments glomerula and mesangial cells were prominently labeled (black arrow in B, magnification 200×). If present, scattered inflammatory cells stained SERPINE1 positive. In the control tissue derived from a kidney with acute tubular damage selected to ensure SERPINE1 expression only proximal tubuli (black arrows in D) were labelled in a considerable heterogenous pattern. Except for some smooth muscle cells SERPINE1 spares all other compartments (Figure 9C, D - magnification 25×, 100×, respectively). DAB immunostaining with mAb against SERPINE1 protein. Brown: SERPINE1 positive cells; blue: nuclei (two independent experiments).