Comparing the 55 patients with duodenal adenoma with the 93 patients with duodenal adenocarcinoma showed significant differences in anatomical location (P < 0.01), treatment methods (P < 0.01), BRAF mutation (P = 0.01), Fn (P = 0.03), and mucin phenotype (P < 0.01). The gene discussed is MUC5AC; the disease is duodenal adenocarcinoma.