As illustrated in Figure 4A, the expression of ATP2A1 was negatively correlated with immune infiltration of CD8+ T cells whether in colon adenocarcinoma (COAD) (r = −0.144, p = 3.70e–03) or in rectum adenocarcinoma (READ) (r = −0.249, p = 3.12e–03), and positively correlated with CD4+ T cells (r = 0.242, p = 4.05e–03), dendritic cells (r = 0.239, p = 4.63e–03) in READ, and negatively correlated with macrophage (r = −0.21, p = 1.31e–02). The gene discussed is ATP2A1; the disease is rectum adenocarcinoma.