While the findings of elevated levels of GDF-15 in DM are not new, and GDF-15 levels are also known to increase with metformin use, the significant association with the DM poor physical function group independent of IL-6, TNF-α, and nutrition indicates that it may serve as a potential biomarker for prefrail older adults with DM and poor physical function [20]. The gene discussed is IL6; the disease is diabetes mellitus.