Antibody testing in patients with suspected APS entails two immunoassays and a functional coagulation assay: IgG or IgM anticardiolipin antibodies (detected by ELISA), IgG or IgM anti-β2-glycoprotein 1 antibodies (detected by ELISA), and a lupus anticoagulant functional coagulation assay [76]. The gene discussed is CD40LG; the disease is systemic lupus erythematosus.