Data from randomized controlled trials indicate that real-time CGM use is associated with QoL and/or glycemic benefits for patients with insulin-treated T1D or T2D.13–18 To date, most real-world studies have been limited to anonymized cloud data and lack supportive laboratory tests or robust QoL data.19–21 In the Landmark study, we examined glycemic data and QoL outcomes among patients who were using intensive insulin therapy (IIT) to manage their T1D or T2D and began using a real-time CGM system. This evidence concerns the gene INS and type 1 diabetes mellitus.