IL17A and Stroke: Moreover, 3–5 days after stroke, IL-17-producing cells and IL-17A–positive lymphocytes are present in the brain parenchyma (Li et al., 2005; Sutton et al., 2009; Gelderblom et al., 2012), probably expression of a disparity between IL-17A-producing cells and regulatory T cells (Hu et al., 2014).