Immunohistochemical analysis performed on formalin-fixed paraffin-embedded sections showed that the tumor cells were positive for hepatocyte (Fig. 2D), CEA (Fig. 2E), and cytokine (CK) 8, but negative for AFP (Fig. 2F), CK-Pan, CK7, VM, S100, and HMB45. The gene discussed is AFP; the disease is neoplasm.