TACR1 and glioblastoma: We performed biological studies on the two newly synthesized and tested radiobioconjugates, [177Lu]DOTA-SP(4–11) and [177Lu]DOTA-[Thi8,Met(O2)11]SP(5–11), and showed that they specifically bound with high affinity (in the nanomolar range) to NK-1 receptors expressed on the U373 MG cell line (their Kd values were close to the Kd values of preparations currently used in medical experiments for GBM treatment).