PIK3R1 and Venous thrombosis: Out of the 80 novel nodes, 12 genes have been previously shown to modify in vivo arterial thrombosis and/or bleeding (Cblb, Cttn, Gnai2, Gria1, Itga6, Lat, Lcp2, Ldlr, Pik3cb, Pik3r1, Rock2, Vav1) (23).