The growing importance of these aPL relies in the fact that some patients show a borderline condition: it is not uncommon to find individuals at high clinical suspicion of APS but negative for the three criteria aPL or, in some cases, negative for the solid assays (β2GPI and aCL) and showing an inconclusive LA test. The gene discussed is FASLG; the disease is autoimmune polyendocrinopathy.