[10] First discovered in 1979, EpCAM was initially described as a dominant surface antigen on human colon carcinoma.

[12] EpCAM therefore has many aliases the most notable of which include TACSTD1 (tumor-associated calcium signal transducer 1), CD326 (cluster of differentiation 326), and the 17-1A antigen.

Overexpression of EpCAM does not alter overall total cellular level of cadherins but rather decreases the association of the cadherin/catenin complex in the cytoskeleton.

As EpCAM expression increases, the total amount of α-catenin decreases, whereas cellular β-catenin levels remain constant.

[17] The homotypic adhesive activity has been questioned, as a variety of in vivo and in vitro biochemical experiments have failed to detect trans-interactions.

[21] Active proliferation in a number of epithelial tissues is associated with increased or de novo EpCAM expression.

This is especially evident in tissues that normally reveal no or low levels of EpCAM expression, such as squamous epithelium.

Targets of upregulation include c-myc, e-fabp, and cyclins A & E.[6] This has the effect of promoting tumor growth.

[22] EpCAM may also play a role in epithelial mesenchymal transition (EMT) in tumors, although its exact effects are poorly understood.

[15] It has been suggested that EpCAM expression is downregulated during EMT but then upregulated once the metastasis reaches its future tumor site.

[28] A problem in EpCAM can indirectly cause Lynch syndrome,[29] a genetic disorder that leads to increased risk of cancer.

Mutations in EpCAM have also been associated with congenital tufting enteropathy[30] which causes intractable diarrhea in newborn children.

This article incorporates text from the United States National Library of Medicine, which is in the public domain.