The strengths of the present investigation include the following: 1) a robust characterization of racial and ethnic differences in insulin dynamics, including MCRI, insulin sensitivity, and β‐cell function (all measured by the clamp methodology), in youth with obesity across the spectrum of glucose tolerance, including NGT, IGT, and type 2 diabetes; and 2) a well‐balanced study population according to sex and race and ethnicity (i.e., Black and White). The gene discussed is INS; the disease is type 2 diabetes mellitus.