Hlx inhibits IFNG promoter activity in DERL-7 cells. (A) The human IFNG luciferase construct used in this study consisted of 3.6 kB of a 5′ flanking sequence upstream of the transcriptional start site, the firefly luciferase open-reading frame, and 0.8 kB of the intron 1 enhancer element. (B) DERL-7 cells with Hlx or empty vector were transfected with the IFNG luciferase construct, and luciferase activity was measured after 6-hour stimulation with IL-12/IL-18. Mean ±SD of 1 of 3 representative experiments is shown.