ANGPT1 and peripheral neuropathy: The same research group also studied the therapeutic effect of sildenafil in middle aged diabetic mice with long-term peripheral neuropathy, concluding that sildenafil is likely to contribute to the amelioration of nerve function through angiopoietin-1 (Ang1) and its receptor Tie-2 signaling, promoting the beneficial effects of sildenafil on neurovascular function in diabetic mice [69].