The ghrelin levels were higher in HNF1A–MODY and GCK–MODY than in T1DM and T2DM (p < 0.001 for all comparisons) but lower than in non-diabetic controls (1.02 ± 0.29 ng/ml, p < 0.001 for both comparisons). This evidence concerns the gene HNF1A and type 2 diabetes mellitus.