FASLG and autoimmune polyendocrinopathy: aβ2GPI antibodies are central in many pathogenic APS mechanisms and, although the full pathogenesis of APS is not clear yet, the binding of these aPL antibodies to the antigens on the cell surface of platelets, monocytes, endothelial cells and trophoblasts, triggers intracellular signaling with subsequent activation and alteration of diverse cell functions.