T-cell accumulation can be observed in the thalamus distal to the primary injury site, which has been shown to undergo secondary neuronal degeneration, and it has been found that the infiltration of T cells continues at least two weeks after stroke, with more CD4 + T cells than CD8 + T cells [253], which coincides with the severe period of poststroke secondary neurodegeneration (SND) [339]. This evidence concerns the gene CD4 and stroke disorder.