In APS, B2GPI is considered a major autoantigen based on the following findings: (a) the detection of aPL requires the presence of B2GPI [52]; (b) immunization of mice with human B2GPI could produce APS-like manifestations, including fetal loss and vascular thrombosis [53]; (c) passive transfer of an anti-BPGPI antibody to mice could produce APS-like manifestations [54]. This evidence concerns the gene APOH and autoimmune polyendocrinopathy.