Following a dose-finding study in patients with latent autoimmune diabetes in adults indicating the safety of a primary injection and a booster injection of 20 μg each of recombinant human GAD in a standard vaccine formulation with alum as adjuvant [137], a double-blind randomised study was performed in 35 GAD autoantibody-positive T1D patients who had fasting C-peptide levels >0.1 nmol/L (0.3 ng/mL) within 18 months of diabetes diagnosis. This evidence concerns the gene GAD1 and diabetes mellitus.