Immunosurveillance is generally mediated by Th1 cells and CD8+ T cells, which take effect through recognizing specific antigenic epitopes emerging during malignant tumor progression.[20] However, antigenicity of malignant cells is not sufficient enough to initiate T‐cell‐mediated anticancer immunity directly, and the activation of both naïve CD4+ and CD8+ T cells is dominantly mediated by mature APCs presenting tumor antigens in secondary lymphoid organs. This evidence concerns the gene CD4 and cancer.