Important to note, constitutive Nrf2 activation is caused to a lesser extent by genetic alterations affecting either the Nrf2 inhibitor Keap1 or Nrf2 itself (accounting for 10–15 % in gallbladder and ovarian cancer or in lung cancer up to 30 % of enhanced Nrf2 activation) as well as epigenetic mechanisms accounting for enhanced Nrf2 activity in 20–30 % of tumors [45, 46]. This evidence concerns the gene KEAP1 and lung carcinoma.