PECAM1 and Stroke: The number of BrdU+/CD31+ cells in the ischemic penumbra of hyperforin-treated mice at 28 dpi was significantly decreased after anti-IL-6 intervention (7 ± 1 vs. 4 ± 1, P < 0.05; Figure 3A,B), indicating hyperforin increases post-stroke angiogenesis via IL-6.