PDE4D and Stroke: Interestingly, of the 71 risk genes that were investigated in this study, 70 (Supplementary Tables 1–3), had significant differential exon/junction usage, yet only four genes were common between sexes in all three main causes of stroke: ADD1, ALDH2, nitric oxide synthase 3 (NOS3) and PDE4D (Supplementary Tables 2, 3), indicating that differential exon and junction expression is sex- and stroke cause-specific.