On the other hand, PCSK9 levels were also related to the cardiovascular event rate and urinary excretion of 11-dehydro-thromboxane (Tx) B2, a marker of platelet cyclooxygenase (COX)-1 activity and an indirect marker of platelet activation, in patients with atrial fibrillation [60]. The gene discussed is PCSK9; the disease is atrial fibrillation.