PBL were activated with PHA (5 mg/mL) and each day, from day 1 to day 6, aliquots of viable cells were treated with MoAb90 (10 μg/mL, □), YTH862 (10 μg/mL, ⋄), or anti-Fas MoAb CH11 (1 μg/mL, ○), and measurements of apoptosis were performed as in Fig 6.