{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Sialylated protein HEG homolog 1 or Heart development protein with EGF like domains 1 (HEG1) is a novel calcium binding receptor protein involved in the Cerebral Cavernous Malformations (CCM) pathway and plays a regulatory role in heart and vessel formation by stabilizing endothelial cell junctions. HEG1 is a heavily glycosylated protein that participates in endothelial cell associations that develop the vascular system, and therefore plays a role in angiogenesis and the microenvironment of cellular adhesion."}]},{"type":"paragraph","children":[{"type":"text","value":"The exact role of HEG1 in hepatocellular carcinoma is unclear, however, studies have shown HEG1 indicates poor prognosis and plays important roles in hepatocellular carcinoma invasion, metastasis, and epithelial mesenchymal transition by activating Wnt/β-catenin signaling. HEG1 mucin-like membrane protein has also been found to be a sensitive and specific biomarker for malignant mesothelioma in pleural (lung) and peritoneal (abdominal) membranes, and several other rare locations, where it supports the survival and proliferation of mesothelioma cells. HEG1 is potentially a useful prognostic biomarker and therapeutic target for malignant mesothelioma and hepatocellular, thyroid, and ovarian carcinomas."}]},{"type":"paragraph","children":[{"type":"text","value":"HEG1 has been found to be a highly specific and sensitive marker of epithelioid Malignant Mesothelioma and offers sensitivity comparable to conventional markers for Epithelioid Mesotheliomas, but provides considerably better specificity, such that the diagnosis of epithelioid mesothelioma versus NSCLC and potentially could be confirmed with a combination of HEG1 and a suitable broad spectrum carcinoma marker such as Claudin-4."}]}]}