CD4 and neoplasm: The abundance of tumor-infiltrating activated memory CD4+ T cells, monocyte cells, and activated mast cells in cluster A was significantly higher (all P < 0.05) than that in cluster B. The abundance of naive B cells, regulatory T (Treg) cells, and M0 and M2 macrophages in cluster B was elevated (all P < 0.05) compared to that in cluster A. Furthermore, multiple checkpoint genes were aberrantly expressed between the two subtypes (Fig. 3B).