TGFB1 and pancreas sarcoma: In vitro proliferation of MS1, an endothelial cell line which is derived from a pancreatic sarcoma and expressing surface GARP:TGF-β1 complexes (Figure 5A), was inhibited by recombinant active TGF-β1 (rTGF-β1) in a dose-dependent manner (Figure 5B).