Abstract
In this issue of Developmental Cell, Jun, Nguyen-Ngoc et al. report that embedding human pluripotent stem cell-derived islets with endothelial cells and fibroblasts, which form perfusable microvessels, accelerates β cell functional maturation. Endothelial cell-derived extracellular matrix proteins and BMP2/4 enhance the β cell Ca
⁺ response, insulin secretion, and in vivo graft performance.