PDCD1 and glioblastoma: Recently, we found that epidermal growth factor receptor (EGFR) inhibition in intracranial glioblastoma multiforme (GBM) grown in two xenogeneic mouse models using a PMLA-based nanopolymer blocked the expression of c-Myc and other CSC markers, with a concomitant decrease in PD-L1, the ligand of PD-1 checkpoint [30].