On the other hand, IgA–aPL (IgA–aCL and IgA–aβ2GPI) have been classified as one of the laboratory classification criteria for systemic lupus erythemathosus (SLE) (15) and can be used to distinguish seronegative APS from SLE (16, 17). This evidence concerns the gene FASLG and systemic lupus erythematosus.