In young/adolescent patients affected by type 1 diabetes, the use of these CL insulin delivery systems has been associated with: (i) a reduction in the occurrence of hypoglycemia without increasing the glucose excursions related to meals [38]; (ii) an improvement in the time spent in the range of 70–180 mg/dL, a decrease in the time under (<70 mg/dL) and above (>180 mg/dL) the range and a reduction in overnight hypoglycemia [39] and (iii) a decrease in the levels of glycated hemoglobin (HbA1c) and a concomitant increase in the time spent in the range [40]. The gene discussed is INS; the disease is type 1 diabetes mellitus.