No significant correlation was detected between the sizes of thyroid nodules and serum IGF-1 (r = −0.032, p = 0.771), between the sizes of IGF-1 in nodules (r = −0137, p = 0.225), and also between the sizes of thyroid nodules and IGFBP3 in nodules (r = −0075, p = 0.509). Here, IGFBP3 is linked to thyroid nodule.