CD4 and neoplasm: Several mechanisms of antitumor immunity mediated by CD4+ T cells have been proposed by studies in mouse models, including direct cytotoxicity dependent on recognition of MHC-II+ tumor cells, local secretion of effector cytokines in the TME and providing T cell help for CD8+ T cells13–15; however, how key characteristics such as TCR avidity and cellular differentiation states impact CD4+ T cell-mediated antitumor immunity remains unknown.