PGP and central nervous system cancer: The enhanced antitumor efficacy could be explained by the following aspects: (i) the long circulation in the blood system coming from PEGylated lipid materials on the liposomal vesicles; (ii) the enhanced transport drug across BBB via the adsorptive-mediated endocytosis by PEI and via blocking the expression of P-gp protein by tetrandrine; (iii) the increased intracellular uptake by glioma cells and GSCs via the receptor-mediated endocytosis by VAP.