TGFB1 and neoplasm: In contrast, pro-tumor immune cells such as M2-type macrophages, regulatory T cells (Tregs), and MDSCs (Feng et al., 2025; Flores-Borja and Blair, 2022; Khan et al., 2020) suppress immune responses by secreting inhibitory factors (e.g., TGF-β and IL-10) or depleting essential nutrients.