In a continued effort to study the add-on effects of metformin on macrovascular or microvascular disease in insulin-treated T2DM patients, Kooy et al. [13] randomized 390 T2DM patients, with a mean age of 53 years, to receive metformin (850 mg/day) or placebo and followed them for 4.3 years. The gene discussed is INS; the disease is type 2 diabetes mellitus.