Both Tc1 and Tc2 populations mediate fas-based cytotoxicity after pharmacologic stimulation. Tc1 and Tc2 populations were used as effector cells in standard 4-hour ⁵¹Cr-release assays at the stated E:T ratios with either the murine leukemia/lymphoma cell line L1210 or the fas-transfected L1210 line (L1210-fas) as target. Results shown are for Tc1 and Tc2 populations (day 13 of culture) that were activated for 24 hours with PMA (5 ng/mL) and calcium ionophore (375 ng/mL) before use as effectors in the chromium assay.