Our project is focused on two well defined subgroups of endocrine tumors, gastro-entero-pancreatic neuroendocrine tumors and thyroid tumors. Both raise many clinical challenges which justify a major effort of basic and applied research. One of the main characteristics of neoplastic endocrine cells is to retain most of the structural and functional properties of their normal counterparts. We therefore wish to determine how the maintenance of the endocrine differentiation program may influence tumor initiation and progression. Three main themes are addressed: (a) the analysis of the mechanisms of tumor initiation and early progression, (b) the study of the mechanisms of late progression and (c) the identification and validation of biomarkers and therapeutic targets through large scale technologies. To address these questions, the team relies on an integrated strategy combining in vivo and in vitro experimental approaches with a strong clinical interface.