Interestingly, the use of the anti-CD137 MoAb turned capable of reducing the activation and proliferation of both regulatory T-cells and myeloid-derived suppressor cells [55,103,110,133,134], that recently emerged as not only able to impair T-cell function but also of compromising the ICI efficacy through the impairment of DC function in cancer [135]. This evidence concerns the gene TNFRSF9 and cancer.