highly significantp < 0.0001
Kaplan–Meier ‘survival analysis’ applied to freedom-from-tumors, followed by a stratified log-rank test for equality of survivor function showed a highly significant difference between the Keap1 flox/flox /Nrf2 +/+ and Keap1 flox/flox /Nrf2 −/− groups (χ 2 = 14.5; p < 0.0001).