The malignant growth of Nrf1α−/−- derived tumor is significantly prevented by knockdown of Nrf2, while Nrf1α+/+-bearing tumor is also markedly suppressed by knockout of Nrf2, but appears to be unaffected by a priori constitutive activator of Nrf2 (i.e., caNrf2ΔN). This evidence concerns the gene NFE2L2 and neoplasm.