TGFB1 and neoplasm: These observations indicate that malignant ascites represents more than a simple by-product of tumor growth; it is a dynamic microenvironment where immunosuppressive cells (e.g., myeloid-derived suppressor cells (MDSCs)), regulatory T cells (Tregs), and factors (e.g., TGF-β, IL-10) collectively undermine anti-tumor immunity by promoting T-cell dysfunction and reducing antigen presentation [23].