This complex interacts with TIMP-1-MMP-2 heterodimer to form a heterotrimer to activate gelatinase A. Excessive TIMP-2 inhibits the activation of gelatinase A, but by the formation of a three-molecule complex the presence of an appropriate amount of TIMP-2 appears to be essential for the activation of gelatinase A. Both MMP-2 and TIMP-2 play a role in maintaining the steady state of the liver cell microenvironment; once the balance is broken by pathogenic factors, hepatic fibrosis occurred [33]. The gene discussed is TIMP1; the disease is Hepatic fibrosis.