CD4 and metastatic malignant neoplasm in the lymph nodes: A low-risk score has a protective effect on patients in the study of the clinical and immune characteristics of PCa, especially those who are older, have invasive PCa, no lymph node metastasis, no biochemical recurrence, low central memory CD4+ T cell infiltration, high immature B cell infiltration, high mast cell infiltration, and low plasmacytoid dendritic cell infiltration.