“…For immunohistochemical reactions, the avidin-biotinperoxidase complex method was used. The antibodies against the following markers were used: (1) pankeratin (AEI/AE3) (BioGenex, San Ramon, CA, 1:40 dilution), (2) chromogranin (BioGenex, 1:200 dilution), (3) neuron specific enolase (BioGenex, 1:15 dilution), (4) S100 protein (BioGenex, 1:400 dilution), (5) synaptophysin (BioGenex, 1:80 dilution), (6) Leu 7 (Becton-Dickinson, Mountain View, CA, 1:10 dilution), (7) cytokeratin 7 (DAKO, Carpenteria, CA, 1:20 dilution), and (8) cytokeratin 20 (DAKO, Carpenteria, CA, 1:20 dilution). Appropriate positive control samples were run concurrently for all antibodies tested.…”