Furthermore, the use of fluorescence-labeled substrate peptides showed that, in the early stage of liver fibrosis (Day 3), in situ TG1 activity was markedly enhanced across a widespread area of the liver, whereas TG2 activity increased only in the periportal area (Fig. 3B); in the late stage of liver fibrosis (Day 7 and 14), TG1 activity was distributed throughout the cells, including HC and HSC, whereas TG2 activity was localized in the extracellular space where it was colocalized with collagen (Figs 3B and 4). Here, TGM2 is linked to Hepatic fibrosis.