Since insulitis typically occurs in the early stages of T1DM, before the clinical symptoms (15), and 55% of MacT3 mice completely failed to develop T1DM, compared to 15% of wt (11), to assess whether the protection conferred by TIMP3 overexpression may involve the control of insulitis, the severity of insulitis was measured on the 11th day after MLSD treatment, when the infiltration of immune cells reaches its peak (16). Here, TIMP3 is linked to type 1 diabetes mellitus.