Golgi membrane protein 1, also known as Golgi membrane protein GP73, Golgi phosphoprotein 2, and GOLM1, is a protein that belongs to the GOLM1 / CASC4 family. GOLM1 is widely expressed. It is highly expressed in the colon, prostate, trachea, and stomach. It is expressed at a lower level in testis, muscle, lymphoid tissues, white blood cells, and spleen. It is predominantly expressed by cells of the epithelial lineage. GOLM1 is expressed at a low level in the normal liver. Expression significantly increases in virus (HBV, HCV) infected liver. Expression of GOLM1 does not increase in liver disease due to non-viral causes (alcohol-induced liver disease, autoimmune hepatitis). Increased expression in hepatocytes appears to be a general feature of advanced liver disease. In liver tissue from patients with adult giant-cell hepatitis (GCH), GOLM1 is strongly expressed in hepatocyte-derived syncytial giant cells. GOLM1 is constitutively expressed by biliary epithelial cells but not by hepatocytes.