KRT8 and neoplasm: Moreover, CDX2 is a more specific marker than CK, CK8, CK18, CK19 and BerEP4 because the former antigen is expressed mainly in tumour and normal cells from the GI tract, whereas the latter antigens are expressed in virtually all carcinomas and all non-neoplastic epithelial cells (Latza et al, 1990; Chu and Weiss, 2002).