CD4 and neoplasm: Interestingly, we observed much more immunologic interactions between CD4+T cells with HPV+ tumor cells than with HPV‒ tumor cells, including ligand-receptor pairs associated with immune response (CD74-COPA, CD74-MIF, Type II IFNR-IFNγ), chemotactic signals like chemokines and cytokines (IL21-IL21 receptor, CCL20-CXCR3), and those pivotal for immune regulation (CD274-PDCD1, PDCD1LG2-PDCD1; Fig. 5B).