IL13RA2 and glioblastoma: In addition to integrins, interleukin‐13 receptor α2 (IL‐13Rα2), and neuropilin1 (NRP1), overexpressed in glioma cells (U87MG), have provided attractive targeting sites for improving drug accumulation.[109] However, delivery of the prodrug into glioblastoma always has to consider the drug resistance attributed to the activation of drug efflux transporters such as P‐glycoprotein (P‐gp).[108]The rational design of prodrug systems that covalently conjugate fluorophores and these targeting ligands enables their accumulation and drug release to glioma tumor cells (Table 5).