The KEAP1-Nrf2 pathway is the major regulator of cytoprotective responses to chemical and/or oxidative stresses caused by reactive oxygen species (ROS) and electrophiles. Nrf2 (nuclear factor erythroid 2-related factor 2) is a transcription factor that binds together with small Maf proteins to the antioxidant response element (ARE) in the regulatory regions of cellular defense enzyme genes leading to the activation of a wide rang of cell defense processes; while KEAP1 (Kelch ECH associating protein 1), a negative repressor of Nrf2, is an adaptor protein for a Cul3-based ubiqutitin E3 ligase that binds to Nrf2 and promotes its degradation by the ubiquitin proteasome pathway.