Metformin has been recommended as the first-line drug for patients with type 2 diabetes mellitus (T2DM) due to its cardioprotective effect [73], and recently National Institute for Health and Care Excellence (NICE) recommended prescribing metformin as adjunctive therapy to insulin in overweight or obese patients with T1DM [74]. The gene discussed is INS; the disease is type 1 diabetes mellitus.