A panel of immunostains, including antibodies against keratin 7, βHCG, chromogranin, synaptophysin, S-100 protein, NSE, serotonin, calcitonin, TTF-1, progesteron, and p53 protein was applied to representative sections of the tumor using the avidin-biotin complex technique (tab 1). The gene discussed is CALCA; the disease is neoplasm.