SPP1 and Stroke: Osteopontin, neopterin and myeloperoxidase [40], as well as lipoprotein-associated phospholipase A2 [41], free fatty acid levels [42] and circulating endothelial progenitor cells [43], have all been tested as recurrent stroke predictors with positive results, whereas the data regarding soluble CD40 ligand are inconsistent [40, 44].