In concert with hypercholesterolemia, BDKRB2 and Bdkrb2 could decrease vascular Gch1 expression and protein level by activation of Gi-coupled signaling because hypercholesterolemia and Gi-coupled signaling are both known to down-regulate Gch1 (44–46). Here, BDKRB2 is linked to familial hypercholesterolemia.