In a novel transgenic mouse strain, wherein IKKα ablation is induced by tamoxifen (Tmx) solely in alveolar type II (AT-II) lung epithelial cells, IKKα loss increases the number and size of lung adenomas in response to the chemical carcinogen urethane, whereas IKK-β instead acts as a tumor promoter in this same context. This evidence concerns the gene IKBKB and lung adenoma.