<h4>Background and aims</h4>We aimed to explore whether saxagliptin, a dipeptidyl peptidase-IV inhibitor, could ameliorate glucose fluctuations and maintain β-cell function in T1DM.<h4>Methods and results</h4>A multicentre, open-label, randomised trial was performed, including 184 T1DM patients from six medical centres. The gene discussed is DPP4; the disease is type 1 diabetes mellitus.