IGFBP2, classified as environmentally influenced, mediated part of the association between self-reported race and ethnicity and T2D, consistent with evidence that relative IGFBP2 deficiency favors visceral adiposity and ectopic lipid storage—established risk factors for T2D.52 By contrast, IGFBP3 was genetic ancestry influenced and supported by Mendelian randomization as having a putative causal role in T2D, reflecting inherited regulation of the IGF axis. This evidence concerns the gene IGFBP3 and type 2 diabetes mellitus.