This accumulation results in decreased levels of ornithine decarboxylase (ODC), a rate-limiting enzyme of polyamine biosynthesis and putative oncogene, as well as increases in the polyamine catabolic enzymes SSAT and SMOX, resulting in depletion of the natural polyamine pools and growth inhibition/cytotoxicity in lung cancer cell lines. The gene discussed is ODC1; the disease is lung carcinoma.