RT-PCR for hIL-2 mRNA was performed and the products detected by ethidium gel. The PCR product was isolated (Geneclean) andMwo I restriction enzyme digestion shows that the hIL-2 amplified from the tumor is predominantly derived from the AdCAIL-2 vector. (A) RT-PCR for hIL-2. Lanes 1, 3, 5, and 6: negative controls; lane 2: tumor biopsy sample 7 days postinjection; lane 4: normal donor phytohemagglutinin-activated T lymphocytes; lane 7: AdCAIL-2 plasmid positive control. (B) PCR products from (A) were digested withMwo I. Lane 1: PCR product from tumor biopsy sample; lane 2: normal donor activated T cells; lane 3: plasmid control. The IL-2 in the tumor post injection is predominantly derived from AdCAIL-2 and does not digest with Mwo I.