In many studies published in literature, various antibodies have been evaluated for their putative role in subclassifying NSCLC.12, 13, 14, 15, 16, 17, 18An exhaustive list of IHC markers including TTF1, CK7, and Napsin A for adenocarcinoma and p63, p40, DSC 3, CK 5⁄6, DSG3, and TRIM 29 for squamous differentiation have been evaluated. The gene discussed is TTF1; the disease is adenocarcinoma.