For example, ketoconazole, an antifungal with inhibitory properties on the CYP3A4, has been shown to increase the peak concentrations of both THC and CBD by about twofold, while other drugs, such as the tuberculosis medication rifampin, a CYP3A4 inducer, significantly reduced the plasma levels of THC and CBD [129]. The gene discussed is CYP3A4; the disease is tuberculosis.