CASC3 and glioblastoma: This ability of BTZ to cross the BBB was previously demonstrated in rat brains44 as well as in a pharmacokinetic study of clinical trial enrolled patients where higher concentrations were measured in the GBM tumour tissue than in the corresponding plasma.45 Newer generation proteasome inhibitors such as Ixazomib and marizomib with improved BBB penetrance are now under evaluation in phase I and III clinical trials, respectively.