CIAPIN1 and type 2 diabetes mellitus: In this study, a T2DM mouse model was established by using HFD combined with STZ to investigate effects of Tat-CIAPIN1 protein and we observed that blood glucose, body weight, and HbAlc levels were markedly increased in T2DM mice whereas Tat-CIAPIN1 protein reduced blood glucose, body weight, and HbAlc levels.