Immunohistochemical assay for EMA (Epithelial Membrane Antigen) aims to detect a complex glycosurfactant membrane antigen (MUC1) expressed on the surface of most epithelial cells and their carcinomas. EMA is a highly sensitive marker for epithelial tumors (carcinomas) and is often used in conjunction with CK Pan to confirm the diagnosis. It is also expressed in some non-epithelial cells, such as plasma cells and meningiomas.