Subgroup analysis of the various aPL subtypes within the APS group revealed that the proportion of β2GPI circulating in the reduced state was significantly lower in the APS patients who were positive for both anti-β2GPI and LAC as compared to those positive for anti-β2GPI but not LAC (median 53.58% [IQR 39.18–73.56] [n = 45] versus 74.80% [IQR 60.69–84.51] [n = 29]; P ≤ 0.001) (Figure 5). This evidence concerns the gene APOH and autoimmune polyendocrinopathy.