Mice subjected to chronic social defeat stress (CSDS) develop depression-like symptoms [134,135] and express lower protein levels of Keap1 and Nrf2 in area CA3 in the hippocampus, dentate gyrus, and prefrontal cortex compared to healthy controls [133], indicating that reduced levels of Keap1 and Nrf2 in these brain areas may contribute to the depression-like phenotypes following CSDS. Here, KEAP1 is linked to major depressive disorder.