Therefore, we aimed at developing a 177Lu-labeled NT-derivative, based on our previously reported metabolically stable amino acid sequence NLys-Lys-Pro-Tyr-Tle-Leu [28,29], and studied the applicability of this radiopeptide ([177Lu]NT127, Figure 1) for endoradiotherapy in NTS1-positive HT29-tumor-bearing nude mice. The gene discussed is NTS; the disease is neoplasm.