Immunohistochemistry has a central role for the diagnosis of SCCB through the staining of tumour components by antibody markers targeting the following antigens: neuron-specific enolase (NSE), chromogranin, synaptophysin, serotonin, cytokeratin, S-100 protein, TTF1, EGFR and C-KIT (table 2) [2,9,11,23-28]. The gene discussed is ENO2; the disease is urinary bladder small cell neuroendocrine carcinoma.