In addition, some conventional non-mucinous adenocarcinomas are HNF4α-positive, which include not only TRU-type adenocarcinomas that are double-positive for TTF-1 and HNF4α but also non-TRU-type poorly differentiated (grade 3) adenocarcinomas with frequent loss of SMARCA4 expression. Here, HNF4A is linked to mucinous adenocarcinoma.