HNF4A and lung colloid adenocarcinoma: The HNF4α-positive lung adenocarcinoma cell lines (A549, Calu3, H1651, and H2405) all showed non-mucinous and high-grade morphology, and the A549 cell line showed a marked loss of SMARCA4, indicating that it was a representative cell line of HNF4α-positive, non-mucinous lung adenocarcinoma with high-grade morphology.