An enzyme inducer is a type of drug that increases the metabolic activity of an enzyme either by binding to the  enzyme and activating it, or by increasing the expression of the gene coding for the enzyme.  It is the opposite of an enzyme repressor. There are specific types of enzyme inducers  that create cytoprotective pathways that play a role in prevention and treatment of cancer and other diseases including cardiovascular disease and neurodegenerative diseases. Enzyme inducers can be either naturally occurring or synthetically made.