Tumor specific CTLs suppress the growth of autologous lung tumors in SCID mice. SCID mice were injected with 5 × 105 tumor cells intravenously. At day 5, after tumor foci were established in the lungs, mice were received either 5 × 106 tumor specific or anti-flu CTLs (i.v. injection). At day 20 and 35, 6 mice from each group (I. control; II. tumor only; III. tumor plus flu-specific CTL or IV. tumor plus tumor-specific CTL were sacrificed and lung and liver were excised for further studies. A. Lung weights; B. Histology of normal lung; C. Histology of lung from tumor bearing mice treated with anti-flu specific CTLs and D. Histology of lung from tumor bearing mice treated with tumor specific anti-LT391-06 CTLs. Differences in lung weight between groups was evaluated by the student t-test: II versus III, P < 0.95; II vs. IV, P < 0.001; III vs. IV, P < 0.004.