A recent study reported that bariatric surgery improves disposition index (DI), a score determined by insulin sensitivity times the amount of insulin secreted in response to blood glucose levels, in diabetes-free subjects such that after 2 years post-surgery, it almost matches general population values.297 However, insulin secretion in response to intravenously administered glucose declines in these individuals, implying that the improved DI is a result of the enhanced post-surgery GLP-1 plasma levels. The gene discussed is INS; the disease is diabetes mellitus.