Recently published as the EJNMMI image of the month, cholecystokinin-2 receptor (CCK2R) targeting by [68Ga]Ga-DOTA-MGS5 PET/CT in a patient with extensive disease small cell lung cancer (Di Santo et al. 2024) provides an excellent opportunity to highlight the role gastrin/cholecystokinin-2 receptors as molecular targets. The gene discussed is CCKBR; the disease is small cell lung carcinoma.