Intriguingly, it has also been suggested that increased circulating RANKL may precede T2DM onset and possibly serve as a predictor of T2DM development, an hypothesis needing to be validated, and that OPG concentrations may not precede T2DM, but rather emerge as T2DM occurs, potentially as a compensatory mechanism, which is consistent with the findings from experimental studies [37]. This evidence concerns the gene TNFRSF11B and type 2 diabetes mellitus.