Vascular endothelin‐2 (Angiopep‐2, ANG) peptide from the aprotinin Kunitz domain can specifically target brain cells and bind to low‐density lipoprotein receptor‐associated protein‐1 (LRP1) to achieve targeted delivery, which is overexpressed in the BBB and glioma.209, 210, 211. The gene discussed is ANG; the disease is central nervous system cancer.