PGP and central nervous system cancer: Since regulation of multidrug resistance proteins expression might directly increase chemoresistance of glioma cells or decrease the permeability of the blood brain barrier to chemotherapic drugs, the expression of multidrug resistance proteins MRP1, MRP3, MRP5, PgP and GSTπ was evaluated on U87MG cells and HUVEC after exposure to BRV and LCM IC20.