Epithelial cell adhesion molecule (EpCAM) is a transmembrane glycoprotein mediating Ca2+-independent homotypic cell–cell adhesion in epithelia. EpCAM is also involved in cell signaling, migration, proliferation, and differentiation. Additionally, EpCAM has oncogenic potential via its capacity to upregulate c-myc, e-fabp, and cyclins A & E. Since EpCAM is expressed exclusively in epithelia and epithelial-derived neoplasms, EpCAM can be used as diagnostic marker for various cancers. It appears to play a role in tumorigenesis and metastasis of carcinomas, so it can also act as a potential prognostic marker and as a potential target for immunotherapeutic strategies. EpCAM is often overexpressed in certain carcinomas, including in breast cancer, colon cancer and basal cell carcinoma of the skin. A problem in EpCAM can indirectly cause Lynch syndrome, a genetic disorder that leads to increased risk of cancer. Mutations in EpCAM have also been associated with congenital tufting enteropathy which causes intractable diarrhea in newborn children.