MUC5B and breast cancer: Consistent with the histology, comparison of untreated and siRNA control-treated cells demonstrated no significant differences in expression of BC (KRT5 and TP63), secretory (MUC5AC, MUC5B and SCGB1A1), ciliated (FOXJ1 and DNAI1) and squamous (KRT6B and IVL) markers (Fig. 2f).