Test Details: Immunohistochemical testing helps to identify specific antigens (proteins) within tissue sections utilizing an antigen-specific antibody. Hepatocyte paraffin-1 (Hep Par-1) is a specific marker for liver tissue and hepatocellular tumours. It is also expressed in adrenal gland tumours, mucosal intestinal metaplasia, small intestinal adenocarcinoma and signet ring cell carcinoma, tumours with hepatoid differentiation and yolk sac tumour.