Therefore, we performed this randomized controlled study to investigate the effects of real-time FGM (unblinded FGM) on daily glycemic control and the changes of diet and exercise in patients with type 2 diabetes who were on premixed insulin therapy, and we used retrospective FGM (blinded FGM) as control to exclude the effects of drug adjustment from doctors. This evidence concerns the gene INS and type 2 diabetes mellitus.