To seek alternative to 177Lu radiotherapy (177Lu-DOTATATE, Lutathera, Novartis), we examined a SSTR2-specific drug conjugate (the maytansine-octreotate conjugate PEN-221, Tarveda38,39), which is currently being evaluated for safety and efficacy against SSTR2-overexpressing advanced gastroenteropancreatic, lung, thymus, or other neuroendocrine tumors and against small cell lung cancer or large cell neuroendocrine carcinoma of the lung (ClinicalTrials.gov Identifier: NCT02936323). This evidence concerns the gene SSTR2 and small cell lung carcinoma.