The prevalence of diabetes will rise to ~592 million in 2035. Type 2 diabetes (T2D) is a leading cause of death through its vascular complications. High glucose increases the risk for complications, and thereby suffering for patients and costs for society. It is important that patients with T2D receive an optimal therapy that lowers blood glucose. Metformin is first-line T2D therapy. However, ~30% of patients do not respond to metformin. Currently, there are no biomarkers that predict the response to metformin. We discovered blood-based epigenetic markers that could discriminate between responders/non-responders to metformin in drug-naïve patients with T2D. This epigenetic tool may be further developed to help patients with T2D receive an optimal therapy. The aim of PROCEED is therefore to develop and commercialize our pharmacoepigenetic tool. We expect this biomarker tool to aid clinical decision-making in T2D therapy.