In the scientific literature, we found a strong connection between adipocytokines (in particular adiponectin, visfatin, vaspin and apelin), copeptin, irisin, PAI-1 and zonulin with insulin resistance and PCOS physiopathology, while the role of other proteins (such as resistin, leptin, RBP4, kisspetin and ghrelin) is still controversial. Here, FNDC5 is linked to Insulin resistance.