Finally, REGI�� is a hitherto unrecognized and possibly useful and sensitive marker for mucosal injury and repair. Acknowledgments Atle vB Granlund is the recipient of a PhD grant from the sellckchem Norwegian University of Science and Technology (NTNU) and Ann Elisabeth ?stvik of a PhD grant from The Liaison Committee between the Central Norway Regional Health Authority (RHA) and NTNU. This work was also supported by a research grant from The Liaison Committee between St. Olav’s University Hospital and the Faculty of Medicine, NTNU. Bj?rn Munkvold, Kari Sl?rdahl and Britt Schulze provided excellent technical assistance. The microarray work was carried out with the support from the National Technology Microarray Platform (Norwegian Microarray Consortium) funded by the Functional Genomics Programme (FUGE) of the Norwegian Research Council.

This work was supported in part by a research grant from The Liaison Committee between St. Olav’s University Hospital and the Faculty of Medicine, NTNU. Declaration of interest The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.
Oesophageal cancer is the sixth most frequent cause of cancer death worldwide (Pisani et al, 1993). Most patients with oesophageal cancer in Japan have squamous cell carcinoma (SCC), while most of those in Western countries have adenocarcinoma. Despite improvements in surgical techniques and perioperative management (Akiyama et al, 1994; Ando et al, 2000), and surgery combined with chemotherapy (Ando et al, 2003) and/or radiotherapy (Ishikura et al, 2003), the prognosis remains poor.

Therefore, for oesophageal SCC patients, novel therapies such as molecular-targeted therapy, including small molecule inhibitors of tyrosine kinases or humanised monoclonal antibodies, are very much needed. The HER family of receptor tyrosine kinases consists of four members: EGFR (HER-1), HER-2, HER-3, and HER-4. The HER family-related signalling is reported to play an important role in modulating cell proliferation, survival, Dacomitinib migration, and differentiation. Despite the large number of ligands so far identified for EGFR and HER-3 and -4, no direct ligand for HER-2 has yet been discovered. As HER-2 is the preferred heterodimerisation partner for all other HER family members, increasing evidence suggests that the primary function of HER-2 is as a co-receptor (Tzahar et al, 1996; Graus-Porta et al, 1997). For example, when ligands such as EGF bind to EGFR, EGFR is heterodimerised with HER-2, leading to the subsequent activation of EGFR tyrosine kinase.