A large body of data consider it a paradox that NRF2 inhibits tumor initiation and cancer metastasis via the elimination of ROS and carcinogens but becomes an accomplice in helping tumor cells to withstand high level of ROS and resist apoptosis which can be referred to as the reverse side of the NRF2/KEAP1 signaling pathway. This evidence concerns the gene KEAP1 and neoplasm.