A consistent fraction of these mucins is associated with diseased states, i.e., colon adenocarcinoma (MUC1, MUC2, MUC4, MUC5A/B/C), breast and uterine cancers (MUC1), and lung diseases, which may cause bronchiectasis (MUC) (Fig. 5). Here, MUC4 is linked to uterine cancer.