Specific binding members, particularly antibodies and fragments thereof, which bind to transforming growth factor beta 3 (TGF-β3) are provided, particularly recognizing human and mouse TGF-β3, particularly antibodies and fragments that do not recognize or bind TGF-β1 or TGF-β2. Particular antibodies are provided which specifically recognize and neutralize TGF-β3. These antibodies are useful in the diagnosis and treatment of conditions associated with activated or elevated TGF-β3, including cancer, and for modulating immune cells and immune response, including immune response to cancer or cancer antigens. The anti-TGF-β3 antibodies, variable regions or CDR domain sequences thereof, and fragments thereof may also be used in therapy in combination with chemotherapeutics, immune modulators, or anti-cancer agents and/or with other antibodies or fragments thereof. Antibodies of this type are exemplified by the novel antibodies hereof, including antibody MTGF-β3-9, MTGF-β3-12, MTGF-β3-16, MTGF-β3-17 and MTGF-β3-19, whose sequences are provided herein.
