Test Details: Immunohistochemical testing is carried out on biopsy/resected tissue specimen. This testing helps to identify specific antigens (proteins) within tissue sections utilizing an antigen-specific antibody .Gross cystic disease fluid protein 15 (GCDFP-15) is a prolactin-inducible protein initially isolated from the fluid of cystic disease of the human breast. GCFP-15 is expressed by apocrine cells or cells with apocrine metaplasia and regulated by the androgen receptor. It is expressed in Breast carcinoma Salivary gland tumours, apocrine skin adnexal tumours, apocrine tumours.