NPPB and Crouzon syndrome-acanthosis nigricans syndrome: There is increasing evidence that BNP can mediate peripheral vasodilation and exert antifibrosis, anti-inflammatory, and antioxidative stress effects [2, 3], and altered levels of circulating BNP have been reported to contribute to other diabetic microangiopathy such as diabetic nephropathy (DN), diabetic retinopathy (DR), and CAN [2, 6, 7].