Influence of the exogenous expressed TRAIL depends on the direct cell contact. a ELISA quantification of TRAIL. The supernatants of JB6pcDNA5/FRT TRAIL and JB6pcDNA5/FRT CAT cells were collected after 48 hrs of cultivation. The remaining cells were lysed. Protein contents were determined and both fractions were subjected to ELISA specific for TRAIL. b Caspase activity in Jurkat cells kept in co-culture with JB6pcDNA5/FRT TRAIL and JB6pcDNA5/FRT CAT or the harvested cell culture supernatant were determined. Data are reported in relative fluorescence light units (RFLU) and presented as mean with standard deviation of three independent experiments. p < 0,05 was regarded as statistically significant.