TTF-1 is expressed in the majority of lung adenocarcinomas (where its overexpression is associated with poor prognosis) as well as in small cell carcinomas and a subset of thyroid and central nervous system tumors and also in T cell acute lymphoblastic leukemia [35-37] No approved therapies targeting TTF-1 expression are available. The gene discussed is TTF1; the disease is small cell carcinoma.