(A–F) Representative confocal micrographs of human airway epithelial cells treated with Air (A, B, C) or Smoke (D, E, F) for 14 d (A, D), 21 d (B, E) or 27 d (C, F) during differentiation using ALI conditions and stained for FoxJ1 (green), acetylated-tubulin (white) or nuclei (blue). Scale bar = 30 μm. (G) Quantification of FoxJ1 positive cells treated with Air (white bars) or Smoke (grey bars) for 27 d during differentiation in ALI conditions. N = 3 different lung donors, * P = 0.06, two-tailed Student’s t test. (H) Quantitation of the average number of nuclei / microscopic field in cells treated with Air (white bar) or WCS (grey bar) for 27 days during differentiation. N = 3 different lung donors, N.S., not significant, two-tailed Student’s t-test. (I) Duplex qRT-PCR of FoxJ1 mRNA relative to GAPDH mRNA in cells treated with Air or Smoke for 27 d during differentiation using ALI conditions. N = 8 different lung donors, * P<0.05, two-tailed Student’s t-test. (J) Duplex qRT-PCR of MCIDAS mRNA relative to B2M in human airway epithelial cells treated with Air (white bars) or Smoke (grey bars) for 27 d of differentiation in ALI conditions. N = 8 different lung donors, N.S., not significant, two-tailed Student’s t-test.