For categories of patients, 7 studies (30.4%) limited their subjects to the pediatric group, 6 (26.1%) studies limited them to adult patients, and 10 studies (43.5%) set no limitation on the age of patients in the HNF1A‐MODY studies, and the corresponding numbers for type 2 diabetes studies were 6, 4, and 4, respectively. Here, HNF1A is linked to type 2 diabetes mellitus.