Fig 1: Marker gene expression in lung epithelial cells in air–liquid interface (ALI) culture. Relative gene expression at weeks 1–5 of ALI culture was normalized as aforementioned. Data were pooled from three individual experiments. (A) MUC5AC, (B) MUC16, (C) FOXJ1, (D) CFTR, (E) SCGB1A1. (F) SCGB1A1 protein expression (Green) in an ALI week 3 culture and DAPI nuclear staining (blue). Scale bar = 50 μm * P < 0.05. ** P < 0.01. (W1-W5: culture under ALI conditions for one to five weeks). Mem: membrane support.