RBP4 and Cowden syndrome 1: Patients with CS presented significantly lower fetuin-A concentration and higher circulating FABP4 and RBP4 compared with healthy controls [156.4 ± 60.0 μg/ml vs 260.7 ± 49.6 μg/ml; 79.8 (35.2-156.1) ng/ml vs 27.9 (17.1-36.7) ng/ml and 34 (30-37.7) mg/l vs 25.8 (23.6-27.7) mg/l, respectively].