GRPR and neoplasm: The development of GRPR-targeted radiopharmaceuticals has been focused on using antagonist sequences as targeting vectors because of their potentially higher tumor uptake due to higher in vivo stability (Ghosh et al. 2019) and more binding sites than those available for agonists (Mansi et al. 2009), and/or less short term adverse effects (Chatalic et al. 2016; Mansi et al. 2013).