All cases of mucinous, enteric, and colloid adenocarcinoma were HNF4α-positive, TTF-1-negative, and SMARCA4 retained, and showed a high frequency of KRAS mutations (10/18, 55.6%) and no EGFR mutations (0/18, 0%). The gene discussed is HNF4A; the disease is mucinous adenocarcinoma.