KL and glioblastoma: Ye et al. [128] reported a simple and versatile approach to functionalizing drug-loaded EVs with the pro-apoptotic peptide KLA and the targeted peptide, low-density lipoprotein (LDL), which selectively binds to the LDL receptor (LDLR) overexpressed on the blood–brain barrier (BBB) and the glioblastoma multiforme (GBM) cell lines.