The correlations of immune cells infiltration abundance with OS were analyzed based on univariate Cox regression analysis in the survival package, and the results showed that activated memory CD4 T cells (HR = 0.557, p = 0.013) and CD8 T cells (HR = 0.6, p = 0.021) had significant effect to OS of STAD patients (Figure 1D). The gene discussed is CD8A; the disease is gastric adenocarcinoma.