To determine whether the MUC5B –3 kb RNAPII loading site resides in accessible chromatin in more physiologically relevant models of human airway epithelium, we cultured primary airway epithelial cells derived from patients with interstitial lung disease (ILD; n = 3) and normal controls (Norm; n = 3) at air-liquid interface (ALI). This evidence concerns the gene MUC5B and interstitial lung disease.