CD4 and Stroke: Some authors have focused on both early and late events in the peripheral immune system during stroke in mice and have observed an early activation of splenocytes that conceivably could result in immune-mediated damage in the developing CNS lesion,37 followed by global immunosuppression that affects the spleen, thymus, lymph nodes, and circulation that has been reported as mediated by a stroke-induced apoptosis of CD4+CD28+ cells in lymphoid organs37,38