The Nrf2 antioxidant response pathway is "the primary cellular defense against the cytotoxic effects of oxidative stress." Among other effects, NFE2L2 increases the expression of several antioxidant enzymes. Several drugs that stimulate the NFE2L2 pathway are being studied for treatment of diseases that are caused by oxidative stress, and dimethyl fumarate significantly reduced the progression of disability in multiple sclerosis. Under normal or unstressed conditions, Nrf2 is kept in the cytoplasm by a cluster of proteins that degrade it quickly. Under oxidative stress, Nrf2 is not degraded, but instead travels to the nucleus where it binds to a DNA promoter and initiates transcription of antioxidative genes and their proteins.