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 .P40 is a truncated and nontransactivating p63 isoform. IHC P40 shows nuclear staining. This is positive in squamous, urothelial, myothelial and basal cell differentiation. Part of panel for subtyping non-small cell lung carcinoma.