TGFB1 and neoplasm: The immunosuppressive TME, composed of regulatory T-cells, myeloid-derived suppressor cells, tumor-associated macrophages, and immunosuppressive cytokines such as transforming growth factor-beta (TGF-β) and interleukin-10 (IL-10), further undermines CAR T-cell efficacy by inhibiting T-cell activity and facilitating immune evasion.