SSTR2 and neuroendocrine neoplasm: Studies have shown that SSTR2 is associated with tumorigenesis in stomach and breast cancer and overexpressed in neuroendocrine tumors (Schulz et al., 2000; Skog et al., 2008; Tchoghandjian et al., 2016; Hope et al., 2018; Mohamed and Strosberg, 2019; Yin et al., 2020).