CD40LG and autoimmune polyendocrinopathy: Due to the lack of specificity in clinical manifestations, the diagnosis of APS is based on the occurrence of clinical symptoms and the detection of at least one of the three antiphospholipid antibodies (aPL, “criteria” aPLs), i.e., IgG or IgM isotype antibodies directed against β2-glycoprotein I (aß2GPI) and cardiolipin (aCL), or a positive lupus anticoagulant (LA) functional assay.