CD4 and Sepsis: According to the immune infiltration levels in the two groups (patients with sepsis and healthy controls), activated B cells, activated CD4 T cells, activated CD8 T cells, CD56-bright natural killer cells, CD56-dim natural killer cells, immature B cells, immature dendritic cells, myeloid-derived suppressor cells, monocyte natural killer T cells, T follicular helper cells, type 1 T helper cells, and type 2 T helper cells were down-regulated in the sepsis group.