CD4 and ischemic stroke: The MR analysis outcome revealed that CD24 on switch memory B cell (OR = 1.03, 95% CI: 1.001-1.067, p = 0.041) and CD4 on CD39+ CD4+ Treg (OR = 1.03, 95% CI: 1.002-1.054, p = 0.031) were weakly associated with an increased risk of ischemic stroke (Figure 5).