CCNB2 and nonpapillary renal cell carcinoma: It is known from Fig. 5B that infiltration of several immune cells in ccRCC samples was significantly and positively associated with high CCNB2 expression, including T regulatory cells (Tregs), activated memory CD4 T cells, T follicular helper cells, M0 macrophages, and CD8 T cells (p < 0.05), which was verified in the GSE40435 dataset (Fig. 5C).