CD4 and nonpapillary renal cell carcinoma: The most predominant cell type in the tumor microenvironment of the left-sided ccRCC was T cells (including CD4+ T cells and CD8+ T cells), whereas the most predominant cell type in the tumor microenvironment of the right-sided ccRCC was epithelial cells (Figure 2e and f), suggesting to some extent that there may be a difference in the response to immunotherapy between the left- and right-sided ccRCC and that the left-sided ccRCC may have a better immune response than the right-sided ccRCC.