For example, the levels of T follicular helper cells, CD8+ T cells and activated natural killer (NK) cells, which are correlated with a positive prognosis in BC (48), were higher in Cluster 2 (p < 0.01), whereas the levels of activated mast cells and M2 macrophages (49), which are correlated with a negative prognosis, were higher in Cluster 1 (p < 0.001) (Figure 1F). This evidence concerns the gene CD8A and breast cancer.