Thus, due to this overexpression, NK-1R ligands (e.g., 213Bi-DOTA-[Thi8,Met(O2)11] substance P and radioconjugates of aprepitant) have been developed and used in targeted radionuclide tumor therapy with promising results for selective irradiation to kill cancer cells [6,7,146]. Here, TACR1 is linked to neoplasm.