HAHLH were generated by transfection of cervical cancer HeLa cells with the XRE(TnGCGTG)3-TATA-Luciferase-SV40-Hygromycin plasmid. rnThe plasmid XRE(TnGCGTG)3-TATA -Luc-SVHygro contains a luciferase gene driven by three AhR responsive elements and a hygromycin gene under the control of SV40 promoter. rn