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 .Stains basal cells of prostate and basal / myoepithelial cells of breast and is used to rule out invasion Useful for detecting benign breast proliferations (mosaic-like pattern) versus ductal carcinoma in situ (DCIS) (negative or rarely diffusely positive) .Along with p63, used to detect squamous cell origin in poorly differentiated carcinomas