Although the APS seen as a PAPS or accompanying SLE essentially manifests the same clinical features, there appears to be distinct differences in the two groups of patients which have been summarized in this article. Additionally, the fact that some patients with Sneddon's syndrome, Trousseau's syndrome, or even Addison's disease, may in reality be examples of aPL-related vascular occlusive events has opened new avenues, not only for identification of these patients, but also for more systematic therapeutic regimens.