The term inducer can be a drug or chemical that typically serves to induce or trigger the appropriate gene transcription necessary to synthesize new copies of a particular enzyme, in addition to what quantity may already be present for that enzyme in the body. Subsequently, because more of a particular enzyme may be synthesized due to the activity of an inducer, drugs or chemicals in the body that are substrates of that enzyme may consequently experience increased metabolism and decreased serum concentrations. Nevertheless, depending on the specific inducer it may induce or trigger the synthesis of certain enzymes strongly, moderately, or only weakly.