A transforming growth factor (TGF)-beta2 specific phosphorothioate antisense oligodeoxynucleotide with the sequence 5'-CGGCATGTCTATTTTGTA-3', with potential antineoplastic activity. Trebedersen binds to TGF-beta2 mRNA causing inhibition of protein translation, thereby decreasing TGF-beta2 protein levels; decreasing intratumoral TGF-beta2 levels may result in the inhibition of tumor cell growth and migration, and tumor angiogenesis. TGF-beta2, a cytokine often over-expressed in various malignancies, may play an important role in promoting the growth, progression, and migration of tumor cells.