The TME, enriched in M2-like tumor-associated macrophages (TAMs), regulatory T cells (Tregs), and myeloid-derived suppressor cells (MDSCs), releases suppressive cytokines (TGF-β, IL-10) and depletes essential nutrients (arginine, tryptophan), collectively impairing CAR-T function (91, 92). This evidence concerns the gene TGFB1 and neoplasm.