Fig. 3. The ARE-1 element of the type III promoter is active in the CIITA-positive melanoma lines. Melanoma cells were transiently transfected with Transit-LT1 using 500 ng/ml reporter DNA and then harvested 48 h later for luciferase assays. Wild-type ARE-1 mutant and IRF-E mutant promoter III constructs are as indicated. The wild-type luciferase counts were normalized to unity to display relative fold induction for the mutated promoters.