If needed (e.g. if the carcinoma is poorly differentiated), the pathologist may request additional diagnostic stains, such as TTF-1 for adenocarcinoma, p63/p40 for squamous carcinoma or mucin stain [83]; predictive test(s) can also be requested (e.g. NGS to identify oncogenic alterations). The gene discussed is TTF1; the disease is adenocarcinoma.