In 1994, we reported on a series of patients treated with T-cell therapy (Study #1). This paper (Study #2) is an update of our experience through 1999 in the production of tumor-derived activated cells (TDAC), also called tumor-infiltrating lymphocytes (TIL), from tumor biopsies. TDAC were successfully grown in medium containing Interleukin-2 from 75% of the 366 tumor biopsies tested. There was no significant difference in success (growth to 1 x 10(9) cells) comparing primary and metastatic tumors. Many of the tumors were shipped to the laboratory by overnight delivery from distant sites. Success rate did decrease with the length of time for tumor transport in excess of 24 hours. Certain additional cytokines were tested when cultures did not grow. Interleukin-4 was beneficial in the development of 1 of 4 TDAC cultures which did not grow with IL-2 alone. In order to produce TDAC to treat patients, cells were grown in gas permeable plastic bags or in artificial capillary bioreactor cultures. Approximately 1 x 10(9) were seeded from an initially successful "feasibility study" to bulk produce cells for treatment. Harvest was carried out after about 3 weeks. Sixty-three patients were treated at least once with a minimum of 1 x 10(10) TDAC given by intravenous infusion. On the average, the number of cells per treatment was 3 x 10(10) with a viability of 87%. TDAC cultures contained T cells with variable ratios of CD4 to CD8 cells. Secreted granulocyte-monocyte colony stimulating factor, interferon gamma and tumor necrosis factor alpha were measured in TDAC conditioned medium. Only 34 patients received the full course of 4 TDAC treatments. The cells were well tolerated with mild fever and dyspnea. Partial responses were observed in 8 patients, including the dramatic regression of scalp nodules in a patient with renal cancer. These results showed that therapeutic amounts of TDAC can be produced in cell culture in a reasonable and cost-effective manner. The cells were well tolerated and responses were seen in renal and melanoma patients resistant to IL-2 with bulky, advanced cancer.