SH2B1 and type 2 diabetes mellitus: In addition, chromosomal deletions that eliminate the SH2B1 gene are also associated with severe obesity and insulin resistance in human [18], [19].Genetic deletion of SH2B1 results in severe leptin resistance, insulin resistance, obesity, and type 2 diabetes in mice [20], [21],and neuron-specific restoration of SH2B1 reverses the obesity and type 2 diabetes phenotypes in SH2B1 null mice [22].