Nine biomarkers of inflammation (CDCP1, FGF-21, IL-8, IL-18, eotaxin, MMP-10, TNFRSF9, CCL25, IL-10RB; see Supplementary Table 2 for full biomarker names) were positively associated with depressive symptoms without significant interaction by diabetes type. This evidence concerns the gene FGF21 and diabetes mellitus.