Molecular and functional profiling of human islets: from heterogeneity to human phenotypes.

Efforts to phenotype pancreatic islets have contributed tremendously to our present understanding of endocrine function and diabetes. A continued evolution in approaches to study islet physiology is important given the need to establish reference points for mature islet functionality, understanding biological variation amongst individuals and cells, and the ongoing appreciation of the role for islets in diabetes susceptibility. Recent efforts in islet biology have focused on technological improvements in imaging, molecular profiling and data analysis, along with a push for enhanced transparency and reporting. The integration of these approaches within a classical islet physiology framework, and approaches to link these data with in vivo human phenotypes, will be critical as we move towards a better understanding of islet function in health and disease. Here we discuss what we feel are important issues and useful approaches to consider as we move forward as a field in islet and beta cell phenotyping. Graphical abstract.