The ATF6 Luciferase Reporter cell line is a stably transfected HeLa cell line which expresses Renilla luciferase reporter gene under the transcriptional control of the activating transcription factor 6 (ATF6)-response element. ATF6 is a member of the basic-leucine zipper transcription factor family, which is located in the endoplasmic reticulum (ER) membranes and plays a central role in transcriptional activation of ER molecules. The ATF6 induction by Tunicamycin is shown in Figure 1.