We found that there was an increase in the percentages of Treg cells in peripheral blood circulating CD4+ T cells from patients with sepsis, particularly those with septic shock, and that hemoperfusion with PMX‐F could remove Treg cells.36 Furthermore, the observed recovery of the number of CD4+ T cells and the decrease in the percentage of Treg cells in the CD4+ T‐cell population 24 hours after PMX‐F therapy may be useful prognostic immunological markers for patients with septic shock. Here, CD4 is linked to septic shock.