Percentages of PD-1+CD4+ T cells and PD-1+CD8+ T cells, MFI of PD-1+ CD4+ T cells and PD-1+ CD8+ T cells, APACH II score and SOFA score were significantly higher in non-survivors than survivors among severe septic patients with or without T2DM (P<0.05), the non-survivors of the SS+T2DM group were older than survivors (P<0.05), but within the survivor group or non-survivor group, no difference could be detected between those with T2DM and those without T2DM (P>0.05) (Table 2, Fig 3). This evidence concerns the gene CD4 and type 2 diabetes mellitus.