the hskt-c cells are small , roundish or spindle-like in shape and form monolayer sheets of epithelial pavement cells and produce carcinoembryonic proteins such as carbohydrate antigen 19-9 ( ca 19-9 ) , carcinoembryonic antigen ( cea ) , tissue polypeptide antigen ( tpa ) , etc .
C0014597
epithelial
C0007082
carcinoembryonic antigen