INS and type 1 diabetes mellitus: The concentration of serum insulin was higher in T1D-MSC-treated responder mice (0.82 ± 0.09 ng/ml, P <0.007) and C-MSC-treated responder mice (0.81 ± 0.12 ng/ml, P <0.02) compared with the control group levels (0.39 ± 0.05 ng/ml) 35 days after MSCs or PBS administration (Fig. 5b).