Interestingly, Gu et al., reported that a DC vaccine loaded with tumor exosomes that induce an immunosuppressive effect in leukemia immunotherapy, led to prolonged survival and tumor growth inhibition, accompanied by an increase in tumor-specific CD4+ T cells in a mouse model with myeloid leukemia; however, these protective effects were not induced by tumor exosomes only [40]. This evidence concerns the gene CD4 and leukemia.