HEG1 is a protein on the surface of mesothelial cells that pathologists can stain for in tissue samples. A specific antibody to it has shown high accuracy in research for separating mesothelioma from carcinomas, making it one of the newer positive mesothelioma markers, though it is not yet standard in every laboratory.
Origin
The name comes from a zebrafish gene, heart of glass, that affects heart development; the human gene's full name is heart development protein with EGF-like domains 1. In 2017, researchers in Japan reported an antibody that recognizes a sugar-modified form of HEG1 on mesothelioma cells, and later studies tested it as a diagnostic stain.
Significance in Asbestos Context
Positive markers are stains that light up in mesothelioma, as opposed to negative markers that light up in lung or other carcinomas. Standard positive markers such as calretinin, WT1, D2-40 and cytokeratin 5/6 are useful but imperfect. In published studies, HEG1 staining with the newer antibody was positive in most epithelioid mesotheliomas and rarely positive in lung adenocarcinoma and other carcinomas, which makes it a promising addition to the panel, especially for epithelioid tumors. It is less often positive in sarcomatoid mesothelioma, so it does not solve that harder problem. Because the marker is relatively new and not available everywhere, many pathology reports will not mention it. When it does appear, it is one piece of a panel, read alongside the tumor's appearance and other stains, never a diagnosis by itself.
Example Sentence
Because the calretinin result was weak, the consulting pathologist added HEG1 and claudin-4 stains, and the pattern supported epithelioid mesothelioma rather than metastatic adenocarcinoma.
Related Terms
Immunohistochemistry, Calretinin, Claudin-4, Wilms Tumor 1 (WT-1), Epithelioid, Lung Adenocarcinoma, Pathology Review, GATA3
Notes
- A report without HEG1 is not incomplete; many labs do not offer it yet.
- Ask whether the diagnosis rests on a full panel of positive and negative markers.
- Keep the tissue blocks and slides available for any second review.
In the research library
14 studies in our medical research library mention HEG1 in the title or abstract. Among the most cited:
- HEG1 is a novel mucin-like membrane protein that serves as a diagnostic and therapeutic target for malignant mesotheliomaS. Tsuji, K. Washimi, T. Kageyama, et al, 2017 · Scientific Reports · cited 56 times
- HEG1, BAP1, and MTAP are useful in cytologic diagnosis of malignant mesothelioma with effusionK. Hiroshima, D. Wu, S. Hamakawa, et al, 2021 · Diagnostic Cytopathology · cited 37 times
- HEG1 Is a Highly Specific and Sensitive Marker of Epithelioid Malignant MesotheliomaJ.R. Naso, S. Tsuji, A. Churg, 2020 · The American Journal of Surgical Pathology · cited 31 times
- Identification of mesothelioma-specific sialylated epitope recognized with monoclonal antibody SKM9-2 in a mucin-like membrane protein HEG1R. Matsuura, H. Kaji, A. Tomioka, et al, 2018 · Scientific Reports · cited 16 times
- Membranous HEG1 expression is a useful marker in the differential diagnosis of epithelioid and biphasic malignant mesothelioma versus carcinomasK. Hiroshima, D. Wu, E. Koh, et al, 2021 · Pathology International · cited 12 times
The journals that publish most on it: Pathology International (2), Scientific Reports (2), Frontiers in Immunology (1).
Category: Diagnostic Tools & Biomarkers · All Lexicon terms A–Z
This page is provided for general informational purposes and does not constitute legal advice. Every asbestos case turns on its own facts, exposure history, diagnosis, deadlines, available evidence, and applicable law. Reviewing this page does not create an attorney-client relationship. For advice about your specific situation, call 833-4-ASBESTOS for a free case review.