Interleukin 18 (IL-18)-secreting CAR T cells can modulate the tumor microenvironment as well as enhance an effective endogenous anti-tumor immune response, mainly because the enhanced killing is accompanied by the recruitment of endogenous anti-tumor immune effector cells (e.g., T-cells and macrophages), which achieves a reversal of the immunosuppressive microenvironment. The gene discussed is IL18; the disease is neoplasm.