SYK and Venous thrombosis: Mice embryos presenting with a homozygous targeted mutation in the Syk gene (by deletion of one exon on Syk gene encoding for 41 residues in the Syk kinase domain in embryonic stem cells) die from severe hemorrhages before birth [16], and mice lacking platelet Syk were protected from arterial thrombosis and ischemic stroke [17], highlighting the important role of Syk in platelets.