NF-κB1Δ/Δ mice are more susceptible to urethane-induced lung damage, pro-tumorigenic inflammation and K-Ras oncogenic mutation than WT mice. (a) Real-time PCR assays showing increased expressions of pro-inflammatory cytokines and chemokines in lungs of urethane-treated NF-κB1Δ/Δ mice. Data shown are means ± SD (n ≥ 5; *, p < 0.05; **, p < 0.01). (b) Hema 3 staining assays showing increase in total immune cells, macrophages, and lymphocytes, in BALF from urethane-treated NF-κB1Δ/Δ mice. Representative macrophages and neutrophils and lymphocytes were indicated by the filled arrows, open arrows and arrowheads, respectively. Scale bar: 20 µm. Data shown are means ± SD (n ≥ 5; **, p < 0.01). (c) Histological analysis showing severe lung injury in urethane-treated NF-κB1Δ/Δ mice. Minor histological changes in the lungs of urethane-treated WT mice (i). Severe epithelial cell death, protein leak, thickened alveoli, perivascular edema and hemorrhage in the lungs of urethane-treated NF-κB1Δ/Δ mice (ii–iv). Scale bar: 50 µm. (d) BCATM protein assay showing higher protein concentration in BALF from urethane-treated NF-κB1Δ/Δ mice. Data shown are means ± SD (n = 5; **, p < 0.01). (e) Genomic sequencing showing increased K-Ras mutation frequency in the lungs of urethane-treated NF-κB1Δ/Δ mice. Data shown are means ± SD (n = 4; **, p < 0.01).