We found that the infiltration of CD8+ T cells, activated memory CD4+ T Cells, regulatory T Cells (Tregs), plasma cells, T helper cells, γδ T cells, M1 macrophages and activated NK cells exhibited a significant negative association with ECI, whereas M0/M2 macrophages, monocytes, mast cells, eosinophils, memory B cells, naive CD4+ T cells and resting memory CD4+ T cells showed a significant positive association with ECI at the pan-cancer level (Fig. 4A). Here, CD4 is linked to cancer.