In transgenic mouse aorta, elevated plasma level of apolipoprotein (a) or Lp(a) alone does not cause endothelial dysfunction [88], suggesting that either the plasma levels were too low or, more importantly, other factors are needed to observe the phenomenon, which seems to be supported by studies in adult humans [88] and children with familial hypercholesterolemia [89], where impaired endothelium-dependent vasodilatation was observed in the presence of multiple risk factors in addition to elevated plasma levels of Lp(a). Here, LPA is linked to endothelial dysfunction.