PGP and glioblastoma: After NF-κB nuclear translocation and binding to its recognition site, the promoter of the MDR1 gene is activated, and gene expression is induced.17,18,34,35 Tomita et al. found that CD133 regulates the level of MDR1/P-gp in glioblastoma through the PI3K/AKT-NF/κB signalling pathway, thereby promoting MDR.36 Li et al. reported that PKC DNA could regulate the expression of MDR1/P-gp in CD133-positive osteosarcoma cells through the PI3K/AKT/NF-κB pathway.37 These studies suggest that CD133 is able to regulate MDR1/P-gp through the PI3K/AKT pathway.