Kim et al. reported that mucinous adenocarcinomas without TTF-1 expression can be regarded as non-TRU-type lung adenocarcinomas [12], and Yatabe et al. reported that the representative non-TRU-type lung adenocarcinomas were poorly differentiated and exhibited solid morphology [4]. This evidence concerns the gene TTF1 and colon mucinous adenocarcinoma.