twenty-one examples of neuroendocrine carcinoma of the skin were examined by the unlabeled antibody enzyme method for several neural hormones and peptides , carcinoembryonic antigen , s-100 protein , neuron-specific enolase , and three intermediate filaments : neurofilament , glial fibrillary acidic protein , and cytokeratin .
C0021770
intermediate filaments
C0017626
glial fibrillary acidic protein