A detailed study on how different infusion rates of GLP-1 affect the slope relating (clamped) plasma glucose concentrations to GLP-1-induced insulinotropic responses showed a linear dose–response relationship for both healthy individuals and those with type 2 diabetes, but the slope was three to five times less steep in type 2 diabetes [33]. The gene discussed is GLP1R; the disease is type 2 diabetes mellitus.