TGFB1 and neoplasm: Alternatively, using human tumor antigen-specific CTLs engineered to resist the inhibitory effects of tumor-derived TGF-β by using a retrovirus vector in which the dominant negative TGF-β type II receptor was modified and ineffective produced TGF-β-resistant CTLs that had a functional advantage over unmodified CTLs in the presence of TGF-β-secreting EBV positive lymphoma.