Apart from its direct cytotoxic effects on cancer cells, cyclophosphamide exerts direct immunomodulatory effects on T cells.[122] Various studies showed that treatment with cyclophosphamide followed by the adoptive transfer of tumor-reactive CD4+ T cells led to the eradication of pleural mesothelioma tumors.[123] These studies have demonstrated that the robust antitumor effects are associated with the development of Th1 antitumor immunity. Here, CD4 is linked to cancer.