The revised Sapporo criteria for APS require at least one clinical criterion (vascular thrombosis and/or pregnancy morbidity) and one laboratory criterion, which can be any of the following: lupus anticoagulant (LA), anticardiolipin (aCL) IgG or IgM, or anti-β2-glycoprotein I (aβ2GPI) IgG or IgM, confirmed on two or more occasions, at least 12 weeks apart (1–3). The gene discussed is CD40LG; the disease is autoimmune polyendocrinopathy.