The present study aimed to evaluate the effect of glucose variability on the relationship between the GRI and other glycemic metrics and its clinical implications in a cohort of pediatric and adult patients with T1D using intermittently scanned continuous glucose monitoring (isCGM) treated with continuous subcutaneous insulin infusion (CSII) or multiple daily insulin injections (MDI). The gene discussed is INS; the disease is type 1 diabetes mellitus.