Mutations in Keap1 or Nrf2, which abrogate formation of the Keap1/Nrf2 protein complex or prevent Nrf2 ubiquitination, leading to its constitutive activation, occur in several types of human cancer, and are particularly prominent in squamous cell carcinomas of the lung, contributing to tumor growth and resistance to chemo- and radiation therapy19,20. This evidence concerns the gene NFE2L2 and squamous cell lung carcinoma.