To define the role of NF-κB2 in lung cancer, we exploited NF-κB2–null mice (Nfkb2–/– mice, referred to as NF-κB2–KO mice hereafter) for the impact of NF-κB2 deficiency on lung tumorigenesis induced by ethyl carbamate (also called urethane). Here, NFKB2 is linked to lung carcinoma.