CD4 and stroke disorder: With the use of flow cytometry, different lymphocytic subpopulations among all controls, non-stroke dizziness and stroke patients were analyzed, including CD19+ cells (B cells), CD3+ cells (T cells), CD3+CD4+ cells (CD4+ T cells), CD3+CD8+ cells (CD8+ T cells), CD3+CD4−CD8− cells (Double Negative T cells, DNTs), and immunoregulatory lymphocytes, namely CD19+CD24+CD27+ cells (Bregs), CD3+CD4+CD25+CD127− cells (CD4+ Tregs) and CD3+CD45RA−CD8+CD183+CD62L+ cells (CD8+ Tregs, Figure 1A).