PGP and breast carcinoma: In vivo studies further showed that the FA-decorated nanoparticles selectively accumulated at tumor sites, and thus greatly improved the therapeutic efficacy and diminished off-target effects in tumor-bearing mice.302 Moreover, an FA-decorated liposomal nitroxyl-doxorubicin formulation termed LNDF was reported to remarkably circumvent P-glycoprotein (P-gp)-mediated multidrug resistance and achieve excellent anti-tumor efficacy in FR and Pgp-positive chemo-resistant breast cancer cells.303