Expression of cytolytic mediator mRNAs in bcr-abl–specific CD4⁺ T-cell clones. Expression of perforin, granzyme B, Fas ligand, TNF-, and lymphotoxin-β mRNAs was investigated by RT-PCR, as detailed in Materials and Methods. The mRNAs were extracted from MY-1 (lane 1) and TO-1 (lane 2) after stimulation with the b3a2 peptide and autologous APCs for 5 days. Lane M shows 100-bp ladder markers.