MMP2 (matrix metalloproteinase-2, gelatinase A, CLG4) is an enzyme that functions in extracellular matrix breakdown and inflammation during embryogenesis, reproduction, tissue remodeling, arthritis, chronic airway diseases and metastasis. It plays an important role in inflammation and neovascularization. MMP2 activated by HIV-infected macrophages converts SDF-1 chemokine into a neurotoxic protein that induces neuronal death and inflammation, characterizing HIV-1 dementia. Mutations in MMP2 are correlated with arthritis, osteolysis and Torg-Winchester syndrome. In immunohistochemistry, MMP2 has cytoplasmic positivity in respiratory epithelia, placental tissue and endothelial and stromal cells in many tissues throughout the body. References: Nat. Genet. 28 (3): 261–5, PMID: 11431697; Biochimica et Biophysica Acta. 1705 (2): 69–89, PMID: 15588763; Cardiovascular Research. 2006. 69(3):562–573,DOI: 10.1016/j.cardiores.2005.12.002; Nat Neurosci. 2003 Oct;6(10):1064-71, PMID: 14502291