A positive correlation between glypican-4 levels in serum with glycaemia was established in our research (concerning persons with MetS and without the characteristics of this condition) and elevated the circulating glypican-4 level in prediabetic subjects (in the study of Sakkane et al. [4]), suggesting that this proteoglycan affects the modification of carbohydrate metabolism. The gene discussed is GPC4; the disease is metabolic syndrome.