Novel strategies for β-cell mass restoration in DM therapy can be divided into thefollowing groups: 1) β-cell regeneration and 2) β-cell replacement, which involves thetransplantation of insulin-producing cells differentiated from embryonic stem cells,iPSCs, and non-pancreatic adult cells (Figure 3).β-cell regeneration should restore β-cell mass in vivo, avoidingcomplications involved with tissue matching and surgical procedures. Here, INS is linked to diabetes mellitus.