Furthermore, in an experimental study conducted by Choo and coworkers tariquidar, a P-gp modulator in combination with propylene glycol, 5% dextrose, and ethanol, was able to inhibit P-gp function at the BBB in high doses [63], thus displaying a possible application in improving CNS permeability of drugs employed in neurodegenerative diseases. The gene discussed is PGP; the disease is neurodegenerative disease.