EPCAM and neoplasm: A de novo expression was observed in areas with atypical undifferentiated cells of the squamous epithelium.[8] Whilst in the present study grade III OSCC exhibited an intense membranous staining of EGP40 (EpCAM), this expression can be heterogeneous, i.e. of other origin, probably by a shift in tumor cell differentiation to either mesenchymal or squamous cell phenotype, therefore being expressed only on undifferentiated cells.[2]