From the results of lipid metabolism, we found that GCK‐MODY patients have lower TG than HNF1A‐MODY patients in the follow‐up period, and comparison with type 2 diabetes patients also showed a tendency toward lower TG in GCK‐MODY in the all‐family‐members subgroup (with longer diabetes duration). This evidence concerns the gene GCK and diabetes mellitus.