c-Myc acts in a direct and specific manner at the distal promoter element to influence KIR transcription. (A) Schematics of the full-length and distal promoter fragments with and without the Myc site that were cloned into the pGL3 basic reporter vector. (B) Each pGL3 vector containing full and distal promoter sequences was electroporated into the NKL-cell line, and luciferase expression was determined 6 hours after transfection. Results represent the mean luciferase levels normalized to Renilla signals from 3 independent experiments.