In an exploratory attempt to validate the observed increase in HIF-1α mRNA expression in rodent models, a limited number of formalin-fixed paraffin-embedded liver samples from patients with liver cirrhosis (CLD), acute-on-chronic liver failure (ACLF) and healthy controls were investigated using immunohistochemistry (Figure 3H). This evidence concerns the gene HIF1A and acute-on-chronic liver failure.