In addition to blocking Treg immunosuppression and restoring anti-tumor immunity, anti-GARP:TGF-β1 mAbs could exert unwanted side effects, owing on one hand to their ability to block TGF-β1 activation from non-Treg GARP-expressing cells, and on the other hand to the pleiotropic functions exerted by TGF-β1 in immunity, including adaptive immunity. Here, TGFB1 is linked to neoplasm.