ITGA5 expression was found to be significantly correlated with tumor purity in colon adenocarcinoma (COAD), esophageal carcinoma (ESCA), STAD and rectum adenocarcinoma (READ) (P < 0.05), CD8+ cell in COAD, LIHC and pancreatic adenocarcinoma (PAAD), CD4 + T cells in COAD, PAAD, LIHC, READ and STAD (P < 0.05) (Fig. 3a-f). The gene discussed is CD8A; the disease is pancreatic adenocarcinoma.