The IgA anti-β2-GP1 levels were significantly higher in patients with PAPS and SLE + APS than in those with SLE (p = 0.0005 and p = 0.0000025, respectively), whereas the IgA anti-β2-GP1 values were higher in patients with SLE than in the control group (p = 0.009). The gene discussed is APOH; the disease is systemic lupus erythematosus.