Genes with differential methylation patterns (e.g., hypermethylated in old and hypomethylated in young) across the BBB of old and young poststroke mice include the signaling molecule Prkce, involved in actin cytoskeleton function (migration, adhesion) and actin cytoskeleton modulator Arf6 (both genes hypomethylated in old mice and hypermethylated in young mice), while Cdc42ep4 was hypermethylated in old and hypomethylated in the young post-stroke BBB. Here, CDC42EP4 is linked to stroke disorder.