SERPINA3 (Alpha-1-Antichymotrypsin) is an alpha globulin glycoprotein produced in the liver that functions as a plasma serine protease inhibitor. It functions in tissue repair and helps reduce damage resulting from inflammatory proteolysis. It is also involved in regulating proliferation and chromatin condensation. Mutations in SERPINA3 are associated with Alzheimer's disease, Parkinson’s disease and chronic obstructive pulmonary disease. Deficiency is correlated with liver disease, while upregulation of SERPINA3 potentially plays a role in the progression of prion diseases. Upregulated SERPINA3 is also associated with invasive properties and progression in glioblastoma. SERPINA3 is an inflammatory marker, and in immunohistochemistry of normal tissue it is positive in the cytoplasm and in extracellular deposits in histiocytes and reticulum cells. In cancer, it is positive in glioblastoma, acinar cell carcinomas of the pancreas, salivary gland and breast, and hepatoid adenocarcinomas of the stomach. References: Nucleic Acids Res. 2016 Jan 4;44(D1):D733-45, PMID: 26553804; Scientific Reports. 2017. 7 (15637), DOI: 10.1038/s41598-017-15778-8; Gastroenterology 2013;144:818, PMID: 23295442; Australian & New Zealand Journal of Psychiatry. 2014. Vol. 48(8): 722–734, DOI: 10.1177/0004867414531078; Oncol Lett. 2018 Jan; 15(1): 285–291, PMID: 29399139