Importantly, analysis of SCLC cell lines isolated from lungs of Ad-Cre-inhaled Rb1FL/FLTp53FL/FLRelaFL/FL mice sacrificed at the humane endpoint revealed efficient ablation of RelA, showing that RelA-deficient cells can give rise to SCLC, in contrast to loss of NEMO that appears to be incompatible with SCLC development. This evidence concerns the gene RELA and small cell lung carcinoma.