The major negative sides of Nrf2 activation include promoting bioactivation of xenobiotics whose glucuronide conjugation form is genotoxic and forms adducts with DNA [186–188], neutralizing the chemotherapeutic effects in which oxidative stress plays a significant role in mediating cytotoxicity to cancer cells, and facilitating drug excretion from cell through increasing the expression levels of multidrug resistant pumps. This evidence concerns the gene NFE2L2 and cancer.