Inhibition of cytotoxicity of fusion proteins by anti-FasL, anti-TAG-72, and anti-L6 mAbs. Cytotoxicity against HeLa cells and cytotoxicity against Jurkat cells were shown in 2A and 2B, respectively. NOK-1 (2 μg/ml) and Alf 1.2 (2 μg/ml) anti-FasL were used as inhibitors against cc49scFv-FasLext (0.8 nM) and L6scFv-FasLext (3.2 nM), respectively. Both strongly inhibited the cytotoxicity. In contrast, cc83 (5 μg/ml) failed to inhibit cytotoxicity against Jurkat cells whereas anti-L6 (5 μg/ml) only inhibited 30% of the cytotoxicity against HeLa cells caused by their respective fusion proteins.