However, neurons and normal brain tissues haverelatively low expression of LDLRs, which makes these receptors significantbiomarkers of GBM.28,29 Indeed, some studies have reportedthat despite their overexpression in the BBB and GBM cells, they arenot overexpressed in astrocytes and microglia.30,31 Within the wide range of receptors belonging to the LDLR family,we highlight the importance of LDLR, LDLR-related protein-1 (LRP-1),and megalin (LRP-2) due to their primary influence in targeting andbinding to peptide ligands, as will be shown in the following sections.32 The gene discussed is LRP1; the disease is glioblastoma.