In a new study published in Journal of Extracellular Vesicles, Chen-Yu Zhang’s group at Nanjing University, School of Life Sciences, and Antonio Vidal-Puig’s group at University of Cambridge report that pancreatic β cells secrete miR-29 family members (miR-29s) via exosomes in response to high levels of free fatty acids (FFAs). Theses β cell-derived exosomal miR-29s regulate glucose homeostasis through their manipulations on glucose output in liver.