On the basis of our observation that pin1 was up-regulated after vascular injury in a HFD/STZ-induced mouse model of T2D and recognition of the inducible effect of pin1 deficiency on VSMC apoptosis in vitro, we suggested that juglone, a Pin1 inhibitor, suppressed in vivo neointimal formation induced by wire injury in T2D. Here, PIN1 is linked to type 2 diabetes mellitus.