For over 20 years, my research has focused on two major types of vesicles: large dense- core vesicles (LDCV) and small synaptic vesicles (SV) using neurons and β cells as models. A primary goal of my research is to elucidate the molecular mechanisms underlying insulin granule trafficking and diabetes. My group has established several cutting-edge tools, including super-resolution imaging, subcellular optogenetics, single-granule fusion/fission assays, membrane capacitance recordings, and novel mouse models. Our recent progress on dynamin points to a crucial function of cortical actin in insulin exocytosis, and this discovery motivates us to further address its molecular principle by investigating the central gene governing cortical actin polymerization.