CD4 and nonpapillary renal cell carcinoma: TIMER analysis was used to clarify the correlation of CXCL13 expression with immune infiltration level in ccRCC, and the results revealed that CXCL13 expression was significantly negatively related to tumor purity and had significant positive correlations with infiltrating levels of B cells, CD8+ T cells, CD4+ T cells, macrophages, neutrophils, and dendritic cells (Figure 6B).