Effect of disruption of individual or paired cis-elements on luciferase activities. (A) MEL cells were transfected with various constructs with the indicated mutations and incubated for 20 hours in the absence of DMSO. Results are the means of three separate experiments. (B) MEL cells were transfected with various mutation constructs and incubated for 20 hours in the presence of DMSO. Fold induction is expressed as the ratio of luciferase activities of cells transfected with indicated constructs in the figure to that obtained with PGL3-Basic. Results are expressed as the means of three separate experiments.