Although some of these inhibitors like Vardenfl showed the accepted result in P-gp blocking and increasing anti-cancer drugs like (paclitaxel and vincristine) intracellular concentration.65 Another alternative to the silence of P-gp is the use of RNAi such as siRNA66 alone or in the combination with nanoparticles application can simulate the effects of inhibitors of P-gp. This evidence concerns the gene PGP and cancer.