Several studies have demonstrated that radiolabeled GRPR antagonists achieve higher tumor uptake and retention in comparison with agonists, despite their significantly inferior internalization in tumor cells (Cescato et al. 2008; Maina et al. 2017; Mansi et al. 2009; Mitran et al. 2020; Nock et al. 2005). This evidence concerns the gene GRPR and neoplasm.