Marion de Jong, Ph.D., is a Professor of Nuclear Biology at the Departments of Nuclear Medicine and Radiology at Erasmus MC in Rotterdam/The Netherlands. She got her PhD degree in 1993 at the Erasmus MC. She is the chair of the SPECTRIM group in molecular imaging and therapy, she was promoted as professor in 2006. Marion de Jong has (co)published more than 300 peer-reviewed papers in international journals (H-Index is 54), holds several patents, obtained many grants and she, as well as her team members, received numerous awards. She was promotor (supervisor) of > 30 past and current PhD students. She is chair of the Translational Molecular Imaging Committee of the European Association of Nuclear Medicine (EANM), member of the Molecular Imaging Committee for the European Society of Radiology, Vice chair of the Nantes Cyclotron (Arronax) Scientific Committee, Member of the national VIDI committee and Chair of the Expert Committee of the Animal Imaging Facility at Erasmus MC. Her major scientific interests include: 1) Translational imaging and radionuclide therapy of tumours and other lesions using theranostic radiopharmaceuticals, with a focus on radiolabelled peptides, and 2) Translational molecular imaging of lesions with focus on nuclear imaging, also in combination with CT, optical imaging and MRI. Selective receptor-targeting radiopeptides have emerged as a very important class of radiopharmaceuticals for molecular imaging and therapy of tumours that overexpress peptide receptors on the cell membrane. After such peptides labeled with diagnostic radionuclides bind to their receptors, they allow visualization of receptor-expressing tumors non-invasively. Peptides labeled with therapeutic beta- or alpha-particle emitters can eradicate receptor-expressing tumors. Erasmus MC has been a pioneer in this field and is still at the forefront of the research field. In the clinic we imaged over 5000 patients using radiolabelled somatostatin analogues, whereas over 1500 treatments were given. Our efforts now concentrate on widening the therapeutic window by combination therapy, increasing the tumour radiation dose and/or decreasing the dose to the normal, healthy, organs. Finally, we aim at curing these now incurable metastasized cancers. To enlarge the panel of tumours to be imaged and treated, we also design and evaluate analogues of other peptides, including bombesin, CCK, and neurotensin analogues that bind to their receptors in a variety of different tumours.