Previous efforts (142) to develop a tissue-engineered islet graft (or bioartificial pancreas) have struggled to achieve clinical translation (58, 61, 63, 143–145), but with recent developments in stem cell and xenogeneic islet technologies (87, 146–155) and the promise of scalable alternative β-cell sources (142, 151, 156, 157), there is a renewed interest in—and progress toward—developing a functional insulin-producing, cell-containing TEG for diabetes treatment (87, 158–161). The gene discussed is INS; the disease is diabetes mellitus.