EPCAM (TACSTD1) is an epithelial membrane glycoprotein involved in cell adhesion that is present on the surface of a variety of epithelial cells. It is expressed in a wide variety of cancers, including: basal cell carcinomas, mammary Paget disease, lung adenocarcinomas, trichoepitheliomas, dermatofibromas, basal-cell carcinomas, cholangiocarcinomas, colorectal carcinomas, and carcinomas of prostate, ovary, endometrium, head and neck, and thyroid. EPCAM is useful for distinguishing epithelial cells (positive) from mesothelial cells (negative). It has also been implicated in the progression of individuals with Lynch Syndrome who hold inherited deletions in the gene. These deletions lead to silencing of the adjacent repair gene MSH2 via transcriptional read-through, which then causes microsatellite instability and colorectal cancer (as well as other malignancies that also frequently arise from Lynch Syndrome). MOC31 and BerEP4 are common monoclonal antibodies to this target. References: JClinPathol 1990,43:213; Acta Neuropathol 1991, 83:46; Dai, 2017; Baeuerle, 2007; Kempers 2010; ModPath 2002, 15:1279