Gregory Kaltsas is currently a Professor of General Medicine-Endocrinology at the National and Kapodistrian University of Athens and the head of the ENETS Center of Excellence for Neuroendocrine Tumors in Athens, Greece. He was trained in general medicine-endocrinology in London, UK, where he developed a special interest in neuroendocrinology and endocrine oncology, particularly in neuroendocrine neoplasms. Professor Kaltsas is also interested in adrenal physiology and adrenal neoplasms. He is a member of the Executive Committee of International Society of Endocrinology (ISE) and of the Advisory Board of ENETS, and acts as an Associate Editor in three international scientific journals. He has published several peer-reviewed articles in the field of neuroendocrine neoplasms and acts as a reviewer for several scientific journals.