The high-risk samples showed a negative association with tumor-infiltrating immune cells, such as CD8 + T cells, CD4 + T cells, neutrophils, B cells, NK cells and M1 macrophages, compared with the low-risk samples, whereas they were positively associated with Tregs, myeloid dendritic cells, monocytes, and cancer-associated fibroblasts, as analyzed by the Wilcoxon signed-rank test (Fig. 6b, Additional file 8: Table S3). Here, CD4 is linked to cancer.