Finally, Smith et al. used a MALDI imaging technique in the study of glomerulonephritis biopsies and were able to identify the presence of alpha-1-antitrypsin (A1AT, coded by SERPINA1 gene) within the cytoplasm of podocyte located in sclerotic glomeruli and suggested a putative role as a marker of podocyte stress (Figure 6b) [11]. Here, SERPINA1 is linked to glomerulonephritis.