Schematic map of the renin enhancer. The location of binding sites (and their original designations Ea–Ee) for transcription factors is shown. Ea stands for enhancer element a and was shown to bind NF-Y. Eb and Ec (enhancer elements b and c) bind to RAR/RXR and may also bind to VDR. Ed binds to the CREB/ATF family of transcription factors, while Ee binds the e-box proteins USF-1 and USF-2.