To better understand the bioenergetics of APS neutrophils, we used metabolic flux analysis to profile neutrophils from (a) healthy controls, (b) patients with APS, (c) patients with circulating aPL antibodies without criteria-defining APS (i.e., “aPL-only” because they have no history of thrombosis or pregnancy morbidity), or (d) patients with thrombosis for reasons other than APS (i.e., “thromb (aPL–)”). The gene discussed is FASLG; the disease is Venous thrombosis.