The reaction is Ca2+ dependent and is classically reported to be the biochemical basis for TG2 involvement in hepatic fibrosis.129 Therefore, amine substrates, such as putrescine and cystamine (competitive inhibitors of the crosslinking activity of the enzyme), have been shown to be protective in ethanol-induced liver injury as well as liver fibrosis induced by CCl4. Here, TGM2 is linked to Hepatic fibrosis.