Immunohistochemical testing was performed, revealing the neoplasm was positive for Chromatogranin A, Synaptophysin and Cytokeratin AE1/AE3 and negative for Epithelial Membrane Antigen (EMA) and Glial Fibrillary Acidic Protein (GFAP) (Fig. 2). The gene discussed is GFAP; the disease is neoplasm.