They Contain Multitudes: The Diverse Roles of CD4+ T Cells in Cancer Immunity

CD4 + T cells, through their diverse functional subsets, play multiple roles in the immune response to cancer. While helper subsets are critical for the initiation and effector phases of antitumor immune responses, immunoregulatory subsets promote tumor growth through multiple mechanisms. Additionally, research investigating the underpinnings of successful immunotherapy points to a substantial involvement of CD4 + T cells. In this article, we examine the varied functions of CD4 + T cells in shaping immune responses to tumors and emphasize the need to more deliberately include CD4 + T cells in the design of cancer therapies.