A total of 15 types of immune cells were significantly different between the ALI samples and control samples (p < 0.05), including activated CD4 T cell, activated CD8 T cell, activated dendritic cell, effector memory CD8 T cell, gamma delta T cell, macrophage, mast cell, MDSC, natural killer cell, natural killer T cell, neutrophil, regulatory T cell, T follicular helper cell, type 1 T helper cell, and type 17 T helper cell (Fig. 7b). The gene discussed is CD8A; the disease is acute respiratory distress syndrome.