INS and type 1 diabetes mellitus: The blood glucose levels of T1DM mice were lowered at 30, 60, 90, and 120 min following treatment with insulin, exenatide, hUCMSCs or hUCMSCs@Ex-4, with the lowest blood glucose levels induced by hUCMSCs@Ex-4 treatment; hUCMSCs@Ex-4 treatment caused lower blood glucose levels versus hUCMSCs treatment (Fig. 2C).