CD44 and glioblastoma: They showed effective BBB permeability of this system and a concentration- and cell cycle phase-dependent selective uptake of HA-CPNs in CD44 positive GBM-patient derived cultures, with a concomitant decrease in cell stemness and capacity for invasion indicating potential use of this system as a therapeutic, but most importantly, providing a safe solution to the inclusion of HA without tumour-promoting effects [39].