PRDM1 and neoplasm: Finally, in the lung of mice with Blimp1 deficiency in T cells, we found an upregulation of CD8+T cells with increased release of cytotoxic mediators able to induce lung tumor cell death.<h4>Conclusions</h4>These data indicate that the tumor microenvironment induces Blimp-1 in immunosuppressive Treg and T effector cells, thereby limiting the therapeutic efficacy of anti-tumor immune responses.