In summary, human single-chain gene transduced T cells were shown: to express the scFv on their surface, to recognize their relevant ligand (tumor-associated antigen) on tumor target cells, to produce cytokines and, to lyze tumor cells. In our earlier review on retargeting T lymphocyte specificity [11], we concluded that a number of questions needed to be answered: (1) Is triggering of cytolysis by CTL or lymphokine production most important to generate anti-cancer effects? Both are important, especially to eliminate bystander cells which do not express tumor-associated antigen [35, 75, 83, 106]. (2) Can targeted CTL traffick and home to the tumor site? Yes, they can. (3) Does “humanization” of mouse mAbs reduce HAMA responses? Our preliminary experiences suggest that this is the case (unpublished data). Significant progress has therefore been made in the laboratory and in clinical tests, and will continue to be made. We are now preparing for the clinical phase I/H testing of in vivo anti-tumor activity of T lymphocytes retargeted by transfer of chimeric receptor genes encoding Ab-type specificity.