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 .PAX-8 is a transcriptional factor involved in the fetal development of the brain, eye, thyroid tissue, kidney, and upper urinary system as well as the Müllerian organs.PAX-8 is a transcriptional factor and a member of the paired box (PAX) family listed in detail with the markers of renal cell tumours. PAX-8 strongly labels all uterine, endocervical and ovarian tumours of Müllerian origin including serous, clear cell and endometrioid carcinomas.