Fig. 4. Schematic representation of the promoter region of human E-cadherin, mouse claudin-3, claudin-4 and claudin-7, and human occludin. The putative transcription start point for each claudin promoter was estimated according to the expressed sequence tag database. Open box, E-box; +1, putative transcription start point; ORF, open reading frame. For the occludin gene, two possible transcription start points have been suggested (Mankertz et al., 2000).