ASCL1 and squamous cell carcinoma: hASH1 expression was positive in 2/16 (12.5%) typical carcinoids, 15/20 (75%) atypical carcinoids, 6/10 (60%) large cell neuroendocrine carcinomas and 31/40 (77.5%) small cell lung carcinoma, respectively, but not in any normal lung tissue (0/10), lung inflammatory pseudotumor (0/49), squamous cell carcinoma (0/30), adenocarcinomas (0/30) or large cell carcinoma (0/20).