The establishment of an immunosuppressive tumor microenvironment is a hallmark feature driving cancer cell evasion of immunosurveillance. In a murine melanoma model, we recently demonstrated that decreased intratumoral CD4 ⁺ T-cell expression of CD40L and interferon γ (IFNγ) is critical to maintain this immunosuppressive microenvironment. Altered effector functions of tumor-associated CD4 ⁺ T cells is essential for B-Raf ^V600E inhibitor-mediated restoration of antitumor immunity.