High levels of protein expression of CTR in primary and secondary GBM cell lines are shown in Figure 5D. In addition, a significant correlation between CTR levels and clinical variables, such as age, IDH wild-type or mutant, and poor prognosis, has been revealed, suggesting that CTR might stratify GBM tumors differently and allow the monitoring of the treatment response. This evidence concerns the gene CALCR and glioblastoma.