The complicated immunosuppressive TME effect on CAR T cells includes a wide array of cellular network and cytokines that induce CAR T-cell exhaustion, inhibit CAR T-cell function, and promote CAR T-cell apoptosis. APRIL, a proliferation-inducing ligand; IL, interleukin; LAG-3, lymphocyte-activation gene-3, MDSCs, myeloid-derived stem cells; NO, nitric oxide; PGE-2, prostaglandin E2; TGF-B, transforming growth factor β; TIM-3, T-cell immunoglobulin mucin-3; Treg, regulatory T cell.