TGFB1 and neoplasm: Pancreatic stellate cells (PSCs) also contribute to the formation of desmoplasia and an immunosuppressive TME by secreting collagen, as well as various growth factors, including transforming growth factor β (TGF-β), platelet-derived growth factor (PDGF), and fibroblast growth factors (FGFs), thereby promoting tumor progression and metastasis.18