MUC5AC and lung adenocarcinoma: MUC5AC is originally a gastric marker which is linked to worse prognosis in different tumour types, such as duodenal adenocarcinoma, cholangiocarcinoma and lung adenocarcinoma.19–21 Recently, it has been described as a strong prognostic factor for AA.10 In the current cohort, the prognostic role of MUC5A was not observed.