Embodiments of the present disclosure relate to compositions and methods of enhancing anti-tumor activities of modified cells, the method comprising: administering an effective amount of the modified cells to a subject having a solid tumor; and administering an effective amount of an agent to the subject, the agent comprising rapamycin, wherein the modified cells inhibit growth of the solid tumor in the subject, and wherein the anti-tumor activities in the subject are greater than those in a subject that is administered with an effective amount of modified cells but without the agent.