CD4 and neoplasm: Furthermore, the application of ICBs targeting effector CD4<sup>+</sup> T cells in Module 1 (αPD-1) and Treg cells in Module 2 (αCTLA-4) in mouse models could help reinvigorate the effector function of Module 1-exhausted CD4<sup>+</sup> T cells and reduce the immunosuppressive function of Module 2-exhausted CD4<sup>+</sup> T cells, ultimately promoting OPSCC tumor regression.