Animal models have added additional empirical evidence for the potential role of GRB14 in obesity: specifically, an analysis of GRB14 expression in adipose tissue found a negative correlation between insulin sensitivity and gene expression [57] in both rodents and humans, and Grb14 knockout mice showed better control of glucose levels (called glucose homoeostasis) [58]. Here, GRB14 is linked to obesity due to melanocortin 4 receptor deficiency.