NF-κB activation by hToll, TIL3, and TIL4. Expression plasmids encoding Fas-hToll, Fas-TIL3, Fas-TIL4, or empty vector were cotransfected with a β-galactosidase (LacZ) expression plasmid into different cell lines in triplicate. Forty-eight hours later cells were lysed from two of the wells and luciferase activity measured as described previously.23 Cells from the third well were fixed with glutaraldehyde (0.5% in phosphate-buffered saline) and stained with X-gal (5-bromo-4-chloro-3-indoxyl-b-D-galactosidase) to obtain relative transfection efficiency.