In a study of 835 patients with type 1 diabetes who were enrolled in the study, the inclusion criteria are given as follows: the duration of type 1 diabetes was at least 1 year, the age was at least 18 years old, BMI was ≥20 kg/m2, they had received multiple daily insulin injections or continuous subcutaneous insulin infusion for at least 6 months, and the level of glycosylated hemoglobin was between 7.0% and 10.0% (53.0–85.8 mmol/mol). This evidence concerns the gene INS and type 1 diabetes mellitus.