Igf2, Mmp14, and Hgf were significantly different between the two groups, and showed interactions with each other (Figure 5C), Igf2 was very close to the gene encoding insulin on human chromosome 11p, which may contribute to regulate the body weight and obesity in children and adults (26); Mmp14 and Hgf were also associated with insulin resistance (27, 28), and these three genes are members of MAPK pathway mentioned above. Here, IGF2 is linked to obesity due to melanocortin 4 receptor deficiency.