With the CIBERSORT algorithm, in comparison with normal samples, pediatric sepsis samples generally contained a higher proportion of monocytes, M0 macrophages, M1 macrophages, M2 macrophages, resting mast cells, activated mast cells, eosinophils and neutrophils, and naïve B cells, CD8+ T cells, resting CD4+ memory T cells, activated CD4+ memory T cells, Trges, resting NK cells, activated NK cells and resting dendritic cells were relatively lower (P < 0.05) (Supplementary Fig. 4a, b). Here, CD4 is linked to Sepsis.