Mice were injected with mouse sarcoma cells amd treated 3 days later when many micro-metastatic tumor foci were evident in the lungs. Lungs on the left were treated with saline. The lungs on the right were treated with lymphokine activated killer (LAK) cells plus recombinant interleukin-2. Greater than 250 sarcoma metastases are seen in the lungs of saline treated mice. This number is significantly reduced to less than 12 in mice receiving LAK cells plus recombinant interleukin-2. Normal mouse l