Lectures given in this XVIIth Servier-IGIS symposium clearly show that research in the field of β-cell differentiation has made promising progress in the past few years. The scientific community has learned a lot regarding pancreas organogenesis and adaptive β-cell responses to physiological or pathological challenges, and useful tools have been developed. Among them, the mass production of functional human pancreatic β cells (from targeted oncogenesis and xenotransplants) and the induction of human embryonic stem cells and human induced pluripotent stem cells to obtain insulin-producing cells. Up till now these approaches have only been successfully used in academic research to increase knowledge about β-cell function in health and disease. The use of artificially differentiated β cells for patient transplantation and the cure of diabetes is still a difficult issue, in particular because of the risk of teratoma formation after transplantation. The development of chemically induced human pluripotent stem cells and the expansion of β cells in 3D multicellular structures and organoids represent interesting ways to counteract this issue.