MUC5AC and lung adenocarcinoma in situ: Furthermore, polarized MUC1 expression was found to decrease with tumor progression from adenomatous hyperplasia to mixed subtypes (adenomatous hyperplasia, bronchioalveolar carcinoma, and adenocarcinoma), whereas the expression of depolarized MUC1, MUC2, MUC5AC, and MUC6 increased with such progression [96,97,98].