Fig 2. Impact of cell density on mature SP-B expression in H441 cells.

Different quantities of H441 cells were seeded as indicated and either left untreated or incubated with 1 μM dexamethasone. After 48 h immunoblotting against SP-B and β-actin was performed. SP-B levels were normalized to β-actin and fold differences compared to 2.5 × 10⁴ dexamethasone-treated cells per cm² were calculated. Means +SD of n = 3 independent experiments are shown. ** p < 0.01 compared to 5 × 10⁴ untreated cells per cm², ## p < 0.01 compared to 1 × 10⁴ dexamethasone-treated cells per cm².