In humans with hypercholesterolemia, ACh-induced vasodilatation is reduced, whereas Gi-independent bradykinin-induced vasodilatation remains unchanged (Matsumoto et al., 2004; Gendron et al., 2007).This indicates a selective loss of some vasorelaxation pathways in hypercholesterolemia (Matsumoto et al., 2004; Gendron et al., 2007). The gene discussed is GNAI1; the disease is familial hypercholesterolemia.