DLK1 and obesity due to melanocortin 4 receptor deficiency: Interestingly, the DLK1 DNA methylation in the maternal side of the placenta indicated the strong correlation with 2 h glucose levels, and the DLK1 DNA methylation in the fetal side of the placenta significantly connected with birth weight, which has already been reported that large birth weight (LBW) is a risk factor of obesity on childhood [25].