Allen et al. established transgenic mice expressing Tle1, Tle5, or both and found that Tle1 transgenic mice spontaneously developed lung cancer, whereas Tle5 transgenic mice were normal (Allen et al., 2006), suggesting that TLE1 might be a lung-specific oncogene and that its tumor-promoting activity might be antagonized by TLE5 (Allen et al., 2006). The gene discussed is TLE5; the disease is lung cancer.