Additive tumoricidal effect of scFvCD7:sFasL with several classes of antileukemia agents. Jurkat cells were treated for 16 hours with scFvCD7:sFasL (5 ng/mL) alone or in combination with vincristin (0.1 ng/mL) (A), farnesyl transferase inhibitor L-744832 (25 μM) (B), and the proteasome inhibitor bortezomib (10 nM) (C). Apoptosis induction was assessed by ΔΨ. The CI was calculated as described in “Materials and methods” and used to determine the cooperative effect of combination treatment.