GRPR and small cell lung carcinoma: GRPR has garnered significant interest in the fields of oncology and nuclear medicine due to its high-density expression in various cancers, including prostate cancer (PC) [26–28], breast cancer (BC) [29–32], small cell lung cancer (SCLC) [33], gastrinoma, gastrointestinal stromal tumors [34, 35], and other cancers [36].