Specific cytotoxic activity of T-cell clone 6.2 against leukemic cells. Patients no. 1 and 2 are leukemia patients with AML-M1 designation. EBV-BLCL and PHA blasts were also tested after culturing with GM-CSF (800 U/mL) + TNF-α (50 U/mL) + IL-4 (500 U/mL) for 72 hours. Adherent PTEC were prepared as targets as indicated in Materials and Methods. Percent specific release of target cells was determined in 4-hour standard Cr release assays.