Since GRB10 has been shown to have parent-of-origin specific effects on expression in various tissues [11], [12], we investigated the transmission patterns of the risk alleles and their effects on insulin and glucose levels during an OGTT, risk for T2D, expression of GRB10 and methylation status in human pancreatic islets, as well as evaluated the effects on islet function through disruption of GRB10 in human pancreatic islets. The gene discussed is GRB10; the disease is type 2 diabetes mellitus.