STAT3 and glioblastoma: Gabrusiewicz et al. demonstrated that glioblastoma stem cell-derived exosomes exhibit an overrepresentation of proteins related to EIF2, eIF4/mTOR, ephrin receptor, and IGF-1 signaling which increase the phosphorylation of STAT3 and ERK1/2 in monocytes, inducing PD-L1 expression and ultimately inhibiting T cell tumor infiltration [79].