CD4 and cancer: Apparently, the activation in these main steps of Cancer Immunity Cycle, such as step 1 (release of cancer cell antigens), step 4 (T cell recruiting, CD8 T cell recruiting, macrophage recruiting, NK cell recruiting, Th1 cell recruiting, dendritic cell recruiting, CD4 T cell recruiting), step 5 (infiltration of immune cells into tumors), step 7 (killing of cancer cells), were significantly higher in cluster 2 than cluster 1 (Figure 2D).