In contrast, the AUC for the combined model incorporating IGF-1, IGFBP-3, and the IGF-1/IGFBP-3 molar ratio demonstrated a significant association with the presence of thyroid nodules in T2DM patients (AUC = 0.619, P < 0.001) (Figure 2, Table 3). This evidence concerns the gene IGF1 and type 2 diabetes mellitus.